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A n swe r s 
623 
answers 
➔ 
 
Chapter 1 Number skills 
Are you ready? 
1 a 
2 
b 
10 
c 
− 
14 
2 a 
− 
8 
b 
3 
c 
− 
10 
3 a 
7.8 
b 
6.74 
c 
10.043 
4 a 
24 
b 
3.29 
c 
56.78218 
5 a 
7.94 
b 
6.23 
c 
182 
6 
2 
-- 7 
37 
----- 
8 a 
1 
----- b 11 
----- c 
1 
1 
----- 1 
-- 6 
9 a b c 
2 
-- 2 
d 
1 
e 
7 
f 
4 
-- 
-- 
-- 
10 a 
0.48 
b 
0.05 
c 
0.189 
11 a 
30 
b 
27 
Exercise 1A — Order of operations 
using whole numbers 
1 a 
16 
b 
0 
c 
9 
d 
9 
e 
12 
f 
18 
g 
480 
h 
0 
i 
4 
j 
30 
k 
12 
l 
18 
m 
26 
n 
68 
o 
12 
p 
80 
q 
4 
r 
48 
s 
2 
t 
3 
2 a 
C 
b 
D 
c 
A 
3 a 
12 
b 
10 
c 
8 
d 
6 
e 
0 
f 
44 
g 
2 
h 
78 
i 
92 
j 
4 
k 
0 
l 
3 
m 
14 
n 
0 
o 
340 
p 
0 
4 
3 
5 
$250, 100 
+ 
2 
× 
(100 
− 
25) 
6 a 
5 
b 
− 
7 
c 
− 
26 
d 
− 
1 
e 
− 
11 
f 
− 
13 
g 
10 
h 
− 
3 
i 
4 
j 
36 
k 
− 
60 
l 
− 
1 
m 
− 
3 
n 
24 
o 
30 
p 
− 
15 
7 a 
− 
2 
b 
− 
11 
c 
− 
11 
d 
13 
e 
− 
3 
f 
2 
g 
1 
h 
6 
i 
− 
9 
j 
− 
3 
k 
− 
4 
8 a 
B 
b 
D 
c 
C 
9 a 
6 
b 
− 
21 
c 
− 
2 
d 
− 
5 
e 
− 
36 
f 
− 
48 
g 
− 
16 
h 
− 
2 
i 
− 
11 
j 
−40 
k 6 l −8 m 17 n −23 o −9 
p 2 q 42 r 1 s 38 t 18 
10 a B b A c D d B e A 
11 a + b × c ÷ d − e +, − 
f ×, + g ×, ÷ h −, − i −, × 
j ×, +, × or ×, ×, − k ÷, − l +, ÷ m −, ÷ 
n −, × or ÷, − o −, × , + 
p −, −, ÷ or +, ×, − 
12 95 metres 13 22°C 
14 a A, B, D b C c C, D 
Exercise 1B — Estimation and rounding 
1 a i 5.9 ii 5.89 iii 5.893 
b i 67.8 ii 67.81 iii 67.806 
c i 712.1 ii 712.14 iii 712.138 
d i 81.1 ii 81.05 iii 81.054 
e i 504.9 ii 504.90 iii 504.896 
2 a 26 b 317 c 1028 d 20 
3 a 3047.3 b 24.7 c 8.3 d 20.0 
4 a i 600 000 ii 570 000 iii 574 000 iv 574 200 
b i 400 000 ii 430 000 iii 431 000 iv 431 000 
c i 30 000 ii 29 000 iii 28 600 iv 28 620 
d i 1 000 000 ii 1 100 000 iii 1 070 000 
iv 1 067 000 
e i 500 000 ii 460 000 iii 459 000 
iv 458 600 
5 a 26 b 320 c 1000 d 20 
6 a 0.0852 b 0.000 580 c 0.000 008 07 
d 0.006 77 e 0.000 027 0 f 0.000 352 
7 a 3 b 800 c 800 d 10 e 400 
f 100 g 1200 h 270 i 100 j 500 
k 110 l 20 m 100 000 n 696 o 60 000 
8 a D b D c D d B 
9 $9000 
Maths Quest challenge (page 13) 
1 10 km/h 
2 11 of digit 0, 21 of digit 1, 20 of all of the other 
digits 
10 Quick Questions 1 
1 −18 2 6 
3 4 4 15 
5 −21 6 10 
7 ×, ÷, +, or +, ÷, × 8 1.7466 
9 0.006 060 10 90 
Exercise 1C — Decimals 
1 a 9.774 b 2.377 c 39.424 d 23 e 23.1 
f 0.6 g −7.2 h 22.976 i 360 j 10 
k 44.95 l 13.2 
2 a 15.22 b 4.57 c 24.96 d 33.18 e 7.26 
3 a 0.4, 0.66, 0.71 b 0.23, 2.3, 23 
c 0.7, 1.04, 1.32 d 1.02, 1.1, 1.22 
e 0.06, 0.5, 0.56 f 0.323, 0.35, 0.4 
4 a 0.24, 0.204, 0.2004 b 0.11, 0.081, 0.062 
c 0.77, 0.707, 0.7 d 0.09, 0.082, 0.0802 
e 1.2304, 1.23, 1.204 f 0.39, 0.3592, 0.359 
5 a C b D c B d A 
6 a b c d e 
-------- 39 
----- 27 
-- 4 
----- 3 
----- 1 
-- 21 
----- 1 
----- 2 
f g h 1 i 2 j 
k l m n o 
----- 
-- 
----------- 31 
----- 1 
----- 71 
----- 
7 a 72% b 31% c 89% d 57% 
e 90% f 6% g 78.2% h 61.75% 
i 0.94% j 135% k 160.2% l 1100% 
m 230% n 575% o 248.5% 
8 a B b B c D 
9 $80.50 
10 a $50 b $46.75 
Maths Quest challenge (page 17) 
1 36 apples 2 125 m2 3 90 s 
Answers 
3 
5 
7 
1 
10 
18 
8 
1 
6 
11 
2 
1 
2 
5 
9 
10 
5 
25 
100 
50 
3 
20 
25 
2 
25 
8 
121 
250 
-------- 963 
1000 
40 
16 
80 
1A 
1C
624 A n swe r s 
answers 
Exercise 1D — Fractions 
1 a b c d e 
-- 9 
-- 8 
-- 1 
-- 4 
-- 7 
----- 7 
----- 1 
f g h i j 
k l m n o 
----- 
-- 
----- 4 
-- 1 
-- 1 
-- 
-- 1 
-- 1 
-- 1 
-- 3 
2 a 4 b 4 c 12 d 6 e 2 
-- 5 
-- 4 
-- 1 
-- 3 
f 4 g 2 h 5 i 9 j 7 
----- 39 
----- 35 
----- 28 
----- 24 
3 a b c d e 
----- 13 
----- 113 
-------- 65 
f g h i j 
----- 
----- 
-- 3 
----- 16 
----- 4 
4 a b c d e 1 
-------- 7 
----- 151 
----- 9 
----- 11 
f g h 1 i j 5 
k l 4 m 1 n 6 o 0 
p 3 
-- 
-- 
----- 
----- 
----- 7 
----- 13 
-- 25 
----- 
5 a 45 b 21 c 30 d 54 e 13 
f 52 g 105 h 14 i 176 j 90 
-- 1 
----- 1 
----- 3 
-- 7 
----- 1 
-- 3 
-- 1 
-- 3 
6 a , , b , , c , , 
-- 
d -- , 13 
----- , 2 
-- , ----- 7 
e ----- 7 
, 19 
----- , 2 
-- , 
----- 
11 
f , 1 -- , 1 ----- 7 
, 1 -- 5 
g ----- 3 
, ----- 7 
, -- 1 
, 
-- 
2 
h , ----- , ----- 5 
i − 1 
-- , − -- 1 
, 
1 
-- 
j − -------- , − ----- 31 
, − ----- 19 
k − 1 
-- , − 1 
-- , ----- 1 
, 
1 
-- 
l − -- , − -- 2 
, -- 2 
, ----- 7 
, 
4 
-- 
7 a 0.75 b 0.8 c 0.45 d 0.56 e 0.775 
f 0.07 g 0.3125 h 0.0375 i 0.3 j 0.705 
k 0.156 25 l 1.5 
-- 3 
8 a 25% b 20% c 37 % d 43 -- 
% e 79% 
-- 7 
f 72% g 73 % h 55% i 83 % j 77 % 
k 71 % l 36 ----- 
% 
9 a D b A c B d B e C 
10 a Year 9 sold 50; Year 10 sold 10. 
b 40 c 
-- 
11 
Exercise 1E — Percentages 
1 a 0.62 b 0.41 c 0.38 d 0.93 e 0.1 
f 0.02 g 0.367 h 0.2125 i 2.5 j 3.157 
k 8 l 0.006 
----- 11 
-- 7 
----- 2 
-------- 21 
2 a b c d e 
-- 1 
----- 5 
-- 3 
-- 1 
f g h i j 
k l m n o 
p 
----- 
-- 
----- 9 
----- 2 
-- 4 
-- 
3 a 5.68 b 208 c 884 d 7.02 e 22.41 
f 42 g 13.06 h 23.375 i 9.1 j 3.28 
k 35.25 l 100 
4 a 75% b 27% c 30% d 64% 
e 62.5% f 2.5% g 43.75% h 64% 
i 72% j 50.4% k 25.8 % l 78.5% 
3 ˙ 
5 a A b D c D d C e A 
6 a 1300 b 1600 c 4600 d 400 e 9 
f 4.5 g 250 h 204 i 900 j 120 
7 a 51.75 b 8236 c 78 d 122.4 
e 162.18 f 690.1 g 1430 h 3.175 
i 119 
8 a 38.25 b 49.4 c 72 d 1279.34 
e 4571 f 96.72 g 1.068 h 368 i 80 
9 a A b C c B 
10 $200 000 
11 $63.75 
10 Quick Questions 2 
1 −9 2 
----- 
1 
28 
3 ----- 
9 
40.003 950 
20 
5 0.67 6 85% 
7 31 
----- 
8567.1631 
50 
9 41 
----- 
10 $59.33 
7 
Exercise 1F — Index notation, square 
roots and higher order roots 
1 a 128 b 243 c 1 000 000 d 256 
e 125 f 2.89 g 39.0625 h 29.791 
i 9.3025 j 0.512 
16 
25 
----- 8 
----- 1 
----- 81 
--------------- 49 
2 a b c d e 
27 
64 
10 000 
----------- 243 
----- 1296 
-------- 27 
--------------- 1 
32 768 
59 049 
f g h i j 
-------- 
144 
128 
64 
2401 
----------- 
3125 
3 a 21 b 0.3 c 9 d 1.2 e 46 
f 0.23 g 26 h 11.5 i 0.24 j 2.7 
4 a 21.56 b 8.12 c 48.52 d 0.99 e 4.46 
f 92.87 g 1.32 h 7.54 i 4.63 j 2.37 
5 a 2.4 b 1.4 c 2.9 d 3 
6 a 1.614 b 9.543 c 2.721 d 3.670 
7 a b c d e 
----- 17 
----- 2 
-- 11 
-- 3 
1 
9 
4 
6 
31 
----- 5 
----- 7 
f g h 
13 
11 
----- 
27 
12 
----- 
15 
8 a 141 b 27.949 c 0.707 788 8 d 20.25 
9 a D b A 
10 35 600 11 778 000 000 km 
Exercise 1G — Further estimation and 
calculator use 
1 a 17.664 b 8.433 c −181.284 d −3.175 
e 6.794 f 3.933 g 19.458 h 0.946 
i 0.397 j 34.291 k −0.448 l 0.086 
m −3.846 n 4.345 o 1.131 
2 a 0.055 56 b 1.994 c −57.09 d 2.188 
e 1.104 f 27.98 g −0.017 30 h 82.53 
i 2.421 
3 a C b A 
Exercise 1H — Ratios 
1 
2 
3 
5 
2 
9 
10 
5 
7 
-- 3 
8 
11 
12 
3 
3 
4 
-- 3 
20 
5 
4 
3 
2 
5 
7 
4 
6 
3 
1 
4 
4 
3 
5 
6 
15 
4 
5 
3 
6 
10 
41 
7 
----- 31 
11 
8 
20 
17 
17 
20 
----- 1 
4 
14 
25 
35 
29 
60 
20 
16 
360 
12 
1 
2 
48 
14 
25 
1 
3 
-- 
1 
4 
8 
2 
10 
3 
20 
20 
6 
5 
1 
2 
20 
3 
10 
20 
50 
5 
25 
11 
16 
----- 1 
4 
12 
6 
15 
30 
3 
5 
5 
19 
----- 5 
18 
17 
5 
8 
4 
79 
100 
40 
25 
7 
9 
10 
8 
3 
4 
3 
3 
10 
5 
1 
2 
4 
3 
4 
-- 1 
3 
9 
3 
7 
-- 4 
11 
2 
5 
-- 
1 
4 
-- 
97 
100 
50 
5 
10 
20 
1 
2 
4 
10 
8 
3 
19 
40 
----- 1 
12 
11 
7 
9 
1 
6 
-- 
a 2:3 b 1:7 c 1:3 d 2:5 e 4:3 
f 4:15 g 40:31 h 36:11 i 8:25 j 100:33
A n swe r s 625 
answers ➔ 
2 
3 
4 D 
5 
6 D 
7 a 120 kg, 150 kg b 50 m, 550 m 
c 86 L, 129 L d 1875 mm, 3125 mm 
e 240 g, 180 g f 3.2 tonnes, 0.4 tonnes 
g $1000, $1500, $1500 h 50 km, 75 km, 125 km 
i 100 mL, 150 mL, 450 mL 
j 33 h, 9 h, 6 h 
8 Maths 2 and Science 6 9 Brother 25, sister 35 
10 a 6, 12, 18 b 40, 80, 120 
c 9.60, 19.20, 28.80 
11 $1350, $1650 
12 67.5°, 90°, 90°, 112.5°; Trapezium 
13 350 g; 500 g; 10 g 
14 a 175:6428 b 37 
Exercise 1I — Rates 
1 a Distance and time b Distance and capacity 
c Money and time d Money and capacity 
e Capacity and time f Money and area 
g Area and time h Runs and overs 
2 
3 $487.62 4 12 5 58.8 
6 1 hour 7 $45 920 8 70 
9 95 hours 
10 a C b A 
11 a 62.5 km/h b 531.25 km/h 
c 17.5 km/h d 96 km/h 
e 13.3 m/s 
12 a 63 km b 296 km 
c 196 km d 2550 km 
e 3600 m 
13 a 8 h b 3 h 
c 6 h 30 min d 8 h 15 min 
e 1 h 10 min 
14 a 12.5 m/s b 30 m/s 
c 16.67 m/s d 27.78 m/s 
e 41.67 m/s f 222.22 m/s 
15 a 18 km/h b 66.6 km/h c 360 km/h 
16 0.75% per month 17 84.5 c/L 
18 11.9 L/100 km 
Exercise 1J — Applications 
1 a −7.3°C b 10.6°C c 19° d 9°C e −14°C 
2 a $190 b +$103.04 
3 a $25.88 b $14.40 c $1.45 d 9 h 
e $786.30 f $77.78 g 3944 mL 
4 209 
5 a of $39 b 1045 c 8 d $24 e 320 g 
6 $457.19 
7 a 3740 b i 8% ii 2356 
c Roald by 2 % d $19 000 
8 1 608 000 000 000 000 000 
9 a B b B c B d D 
10 a 12.5 m b 80 mm × 72 mm 
11 a 7:5:4 
b Jane: $14 000, Annette $10 000, Bernadette $8000 
12 a 4 hours 40 minutes 
b 24.9 km/h 
Summary 
1 grouping symbols 2 point 
3 significant 4 numerator 
5 decimal 6 divide, percentage 
7 amount 8 100 
9 multiply 10 add 
11 ratio 12 highest common factor 
13 quantity 14 rate 
15 per 
Chapter review 
1 a 4 b 38 c 3 d 22 
2 a 51 b 2 c 6 d 20 
3 ×, ÷, − 
4 a 5689.71 b 5700 
5 a 2160 b 2156.6 
6 B and C 
7 a 36.615 b −2.95 
8 a b ----- c ----- 11 
d -------- 73 
e 
31 
-- 23 
----- 93 
-------- 2 
f g h i j 
-------- 
-- 
9 a b 
-- 
10 a 71% b 240% c 93.75% d 16 % 
11 D 
12 a 24 b 383.5 c 373.8 
13 a 0.12 b 0.346 c 0.875 d 8.25 
14 a ----- b 1 ----- 3 
c 
2 
-- 
15 182.4 16 1500 
17 a 57%, ----- , 0.6 b 23 -- 1 
%, ----- 
6 
, 0.245 
18 a 0.83, 82%, -- b ----- 
5 
, 0.416, 41% 
19 a 36 b 2.05 c 1.1 
20 a 267.968 75 b 875 000 
21 a i 4.273 ii 4.27 b i 0.380 ii 0.380 
22 a C b A c B 
23 Miss Alan $5600, Mr Bradley $4200, 
Mrs Cato $9800, Ms Dawn $8400 
24 a Karen’s b 450 km c 37.5 L 
25 1.25 L for $3.60 
26 a 20 m/s b 54 km/h c 4.58 c/g 
d 0.4%/month e 11.76 km/L 
27 C 28 B 
29 42 litres 30 219 030 litres 
31 a 567 km b 84 km/h c $94.40 
32 C and D 33 10 − 23 × −2 
34 Any number between 15.395 and 15.405. 
35 Any decimal greater than 0.6 and less than . 
36 
37 45 38 A 39 150% 
40 31.5 41 20 
a 6:1 b 13:15 c 4:1 d 5:1 e 1:2 
f 20:3 g 1:6 h 5:3 i 5:1 j 11:5 
k 43:20 l 1:200 
a 3:4 b 8:7 c 2:3 d 28:25 e 9:2 
f 2:7 g 10:3 h 33:16 i 23:15 j 16:65 
a 1:4 b 6:5 c 100:39 d 23:2 e 1:12 
f 63:125 g 400:21 h 20:1 i 1:15 j 54:5 
a 18.4 points/game b $12.85/hour 
c 7.2 L/hour d 48c/min 
e 9.7 L/100 km f 85c/kg 
g $2.48/km h 8.5 kg/ha 
i 3.8 runs/over j 34 cm/year 
2 
3 
-- 
1 
2 
-- 
7 
8 
-- 6 
25 
20 
200 
125 
13 
100 
-------- 3 
4 
40 
250 
5 
5 
8 
-- 4 
5 
2 
3 
-- 
13 
25 
10 
7 
29 
50 
2 
25 
4 
5 
12 
. 
0.6 
6 
7 
-- 
1D 
1J
626 A n swe r s 
answers 
Chapter 2 Indices 
Are you ready? 
1 a Base is 3, power is 4 
b Base is 2, power is 5 
c Base is 15, power is 7 
2 a 16 b 125 c 4096 
3 a 3 b 11 c 17 
4 a 8 b 10 c 5 
5 a 2 b 5 c 9 
6 a 4 b 6 c 1 
7 a 5 b 10 c 6 
d 4 e 2 f 5 
8 a 4.7958 b 10.0995 c 6.3246 
d 3.9149 e 2.2240 f 4.9324 
Exercise 2A — What are indices? 
1 The second option is better. 
2 a 39 b 56 c 1213 
Exercise 2B — Powers and bases 
1 a Base = 4, power = 7 b Base = 3, power = 8 
c Base = 5, power = 0 d Base = 7, power = 12 
e Base = 123, power = 3 f Base = 2, power = 141 
g Base = p, power = 3 h Base = e, power = 7 
i Base = k, power = 10 j Base = q, power = 4 
2 a 36 b 74 c e4 d 55 
e 4a7 f 7y3 
3 a 3 × 3 b 4 × 4 × 4 × 4 × 4 
c 9 × 9 × 9 d 8 × 8 × 8 × 8 
e p × p × p × p × p × p × p f b × b × b 
g k × k × k × k × k h a × a × a × a 
4 a 16 b 2187 c 1000 d 512 
e 256 f 125 g 1296 h 1 
5 a B b D 
6 a 6a2b3 b 4p3r4 c 15e4y2 d 30c3z 
e 7d2f 5g2 f 18h2i3j3 g 35ek3m2 h 40n5p2q 
7 a 3 × e × e × e × e × e × e × f × f 
b 4 × p × p × p × p × q 
c 7 × t × t × p × p × p × p × p 
d 12 × q × q × q × r × r × t 
e 12 × a × a × b × b × b × b × c × c × c 
Exercise 2C — Multiplication using 
indices 
1 a 3 × 3 × 3 × 3 × 3 × 3 = 36 
b e × e × e × e × e × e × e = e7 
c f × f × f × f × f × f × f × f = f 8 
2 a 29 b 317 c 610 d 106 e 49 
f g13 g h3 h a12 i p14 j q49 
3 a 212 b 318 c 917 d 1011 e 126 
f a11 g p21 h e22 i g26 j e36 
k 4b13 l 7d16 
4 a A, D b B 
5 a 25p11 b 15x8 c 63y10 d 18p8 
e 70t6 f 20q15 
6 a 6a6e9 b 8p7h12 c 80m8 d 6g3h7 
e 30p6q8 
7 a 4u5 + 28u2 b 9y9d + 45y8d 
c 7b4c4 + 35b3c2 d 4s2t3 − 20s3t 
e 5h20v2 + 10h10v3 − 15h10v2 
Maths Quest challenge (page 59) 
1 $10 240 2 525, 526, 527 3 3 1 
-- 
minutes 
2 
Exercise 2D — Division using indices 
1 a b4 b w3 c q0 or 1 
2 a 5 b 77 c s4 d z5 e i3 
f 6 g 104 h c4 i t33 j h77 
k b70 l f 900 
3 a 4x2 b 6y2 c 9w7 d 3q4 e 10f 9 
f 10h90 g 2j10 h 5p10 i 8g3 j 
3b5 
-------- 
2 
--------- 10n90 
9m4 
2 
k l 
------------- 
7 
4 a D b A, D 
5 a 5p4 b 6r4 c 5a3 d 3b6 e 10r4 
f 9q 
6 a 2p5 b c d 
8b5 
3 
-------- 5m10n5 
----------------- 9x8y 
6 
----------- 4 p2rs2 
4hk2 
3 
---------------- 9a5b3c 
e f 3j5f 3 g h 
----------- 
4 
3 
----------------- 
20 f 6g2h4 
i 
----------------------- 
9 
Exercise 2E — Zero index 
1 a 1 b 1 c 1 d 1 
2 a 1 b 1 c 1 d 1 
3 a 3 b 12 c 4 d 17 
4 a 4r3 b 5 c 13 d 
-- 
5 
3 
2 
e 3 f 2b2 g ----- 
dh1 
2 
5 a 1 b 1 c 1 d 4 
e 4 f 10 
6 a 1 b -- c 2 
d 
3 
2 
-- 
3 
3a2 
-------- 
2 
2r5 
3 
-- r6 
-------- g 
---- 2d9 f 4 
e f g h 
2 
7 a D b A c D 
8 a 1 b 2 c 2 d 2 
h2 
q4 
e 2 f ----- g h 
2 
i v2 j 2x6 
Maths Quest challenge (page 66) 
1 33 
2 
5 14 15 8 
4 18 11 9 
17 7 6 12 
16 3 10 13 
2 
3 
-------------- 
3 
----- n3 
5 
----- 
5 
1 
2 
3 3 -- 
hours 
4 When a = 1, a3 × a2 = 1, and a6 = 1. Also when 
a = 0, a3 × a2 = 0, and a6 = 0. But if a ≠ 1, a ≠ 0, 
then a3 × a2 equals a6 ÷ a. This will have a different 
answer to a6.
A n swe r s 627 
answers ➔ 
10 Quick Questions 1 
1 b 2 7 3 z5 
4 27 5 262.144 6 1639 
7 g8 8 p10 9 1 
10 q 
Exercise 2F — Raising a power to 
another power 
1 a x6 b f 80 c s100 
d r144 e a10b15 f p5q15 
g g15h10 h 81w36q8 i 25e10r4q8 
2 a p10q6 b r15w9 c x10n18 
d j18k12 e q4r20 f h24j16 
g f 16g21 h t10u8 i i15j12 
3 a 220 b s33 c a21 d b24 
e y66 f g39 g 324x20 
h 216d27 i 40 000r54 
4 a B b B, D c D 
5 a b6 b m4 c n3 d p8 
e f 17 f g6 g y9 h y2 
i c20 j g7 k k14 l p16 
6 a b c d 
e f 
Exercise 2G — Negative indices 
1 a -- b -- 
1 
c ---- d 
1 
2 a 5−1 b 8−1 c a−1 d q−1 
3 a -- b -- 1 
c 1 
-- d 
1 
4 a b c d 
--- 
--- 
-- 
5 a 7−2 b y−5 c z−4 d v−3 
6 a b c d 
------ 1 
e f g h 
p5 ----- 21g6 
7 a b c d 
e s f g3r6 h 
------- 
----- 
Maths Quest challenge (page 71) 
1 8 2 6 3 2 
Exercise 2H — Square roots and cube 
roots 
1 a 2 b 4 c 10 d 7 e 9 f 12 
2 a b b c c d d a2 
3 a 2t b 3b c 10f d x 
e 25 f 16y4 
4 a 2 b 1 c 4 d 35 
e 5 f 2.1544 g 2.4662 h 2.7144 
5 a e b t c b d y2 
6 a 2p b 4x c 5at d 10p2 
e 6y2 f 15z2t g 3ed2 h 7f 2g2 
7 a B b D c A 
8 a 25y b 12x c 5 d 8x 
10 Quick Questions 2 
1 q9 2 p2 3 5 
4 a40 5 2s6t3 6 
7 8q−4 8 10 9 3 
10 2g2 
Exercise 2I — Scientific notation 
(standard form) 
1 a 3.15 × 102 b 4.3 × 103 c 6.7 × 1012 
d 4.5 × 100 e 2.3 × 10 f 9.0 × 1016 
g 6.78 × 104 h 1.22 × 10−2 i 7.89 × 10−3 
j 2.3456 × 10−1 k 7.8 × 10−4 l 5.0 × 10−6 
2 a 3500 b 670 c 9010 
d 86 500 e 700 000 f 78 
g 0.012 35 h 0.008 996 54 i 0.4323 
j 0.000 07 k 0.000 432 l 0.000 008 765 
3 a 1.53 × 109 b 1.035 × 105 
c 4.68 × 108 d 1.05 × 1030 
e 5.22 × 104 f 3.513 123 × 1016 
g 4.0815 × 1010 h 2.1736 × 1013 
i 2.72 × 1012 j 4.08 × 107 
k 1.495 × 1042 l 1.5615 × 106 
4 a 9.0 × 10 b 2.077 × 10 c 2.0 × 104 
d 4.0 × 102 e 2.6 × 105 f 5.0 × 102 
g 1.73 × 1013 h 2.241 04 × 102 i 1.27 × 10 
j 1.9 × 104 k 2.41 × 10 l 8.0 × 1013 
5 a 1.62 × 1019 b 1.3293 × 1013 
c 1.606 406 × 1037 d 1.760 54 × 1022 
e 8.1862 × 108 f 9.633 12 × 1018 
g 2.093 75 × 102 h 2.127 65 × 102 
i 2.0 × 10−10 j 4.0 × 10−2 
k 1.302 857 × 1010 l 4.3 × 1013 
6 a A b C 
7 1.0 × 107 
8 9.72 × 10–8, 4.009 × 10–6, 5.72 × 1014, 5.78 × 1014, 
1.3 × 1016, 4.13 × 1072 
9 a 2.544 × 106 km b 9.2856 × 108 km 
10 8.849 × 103 hours 
Summary 
1 power 2 index form 3 calculator 
4 add 5 subtract 6 base 
7 raising 8 variations 9 fractional, 
10 multiply 11 cube 12 square root, 
13 cube root, 14 Scientific notation 
15 negative 
Chapter review 
1 The second option is better. 
2 a 4 b 5 c a d x 
3 a 3 b 12 c 89 d 0 
4 a 54 b 77 c g5 d h3j5 
5 a 25 b 16 c 32 d 1000 e 81 
25b8 
d6 ----------- 25h20 
4 j4 ------------- 8k15 
27t12 ------------ 49 p18 
64q44 -------------- 
25y14 
9z26 ------------- 256a12 
2401c20 ------------------- 
1 
4 
6 
1 
m 
p 
1 
x 
a 
b 
w 
1 
25 
----- 1 
8 
1 
g4 ----- 1 
k6 ---- 
1 
x3 ---- 1 
y4 ---- 1 
z6 ---- 1 
q7 ----- 
1 
m4 ------ 3 
------ 5q 
m2 p 
6m 
1 
a 
-- 36 
----------- 20 
h3 p 
-------- 7 p4 
15a 
--------- 
q4 b4 1 
p 
--- 
1 
an 
----- 
a 
1 
2 
-- 
a 
1 
3 
-- 
2A 
2I
628 A n swe r s 
answers 
6 a 16 b 35 
7 a b10 b m11 c k8 d f 14 
e h10 f 6q17 g 35w29 h 12e5p8 
8 a a3 b t4 c r7 d p3 
e f 5 f y90 g m10 h g7 
i x j d6 k t5 l p5 
9 a 1 b 1 c 1 d 1 
e 1 f a g 3 h 3 
i 199 j a7 k 1 l pr 
m a9b4 n j8m3 
10 a b8 b a24 c k70 d j200 
e a15b6 f m14n24 g s3t18 h q10p300 
11 C 
12 a b c d 
13 a x−1 b 2y−4 c z−3 
d 135p−3q−3 
14 a 10 b 6 c a d b 
e 7f 2 f 3 g 10 h x 
i 2d j 4f 2g 
15 a 4.5 × 104 b 2.3 × 102 c 7.5 × 108 
d 3.7 × 10−3 
16 a 3400 b 789 000 c 345 600 000 
d 0.0043 
17 C 
18 A 
19 1.4 × 1012 
20 4.167 × 108 
21 9.16 × 107 km 
22 1.03 × 1012, 4.601 × 1011, 4.06 × 1011, 7.34 × 10–3 
Chapter 3 Geometry 
Are you ready? 
1 GKP or PKG 
2 a Reflex b Right c Obtuse 
d Acute e Straight f Reflex 
3 a 55° b 145° 
4 a x = 62° b a = 77°, b = 103° 
c y = 45° 
5 a i Co-interior ii Corresponding iii Alternate 
b a = 52°, b = 128°, c = 52°, d = 128° 
c Line AB is not parallel to line CD. For parallel 
lines, alternate angles should be equal. 
6 a a = 84° b b = 67° c c = 75° 
Exercise 3A — Angle review 
1 a ∠AOB or ∠BOA b ∠MON or ∠NOM 
c ∠BAC or ∠CAB 
2 a Reflex b Acute c Straight 
d Obtuse e Obtuse f Reflex 
g Obtuse h Right i Reflex 
j Revolution 
3 a Complementary = 70°, supplementary = 160° 
b Complementary = 45°, supplementary = 135° 
c Complementary = 0°, supplementary = 90° 
d Complementary = 18°, supplementary = 108° 
e Complementary = 1°, supplementary = 91° 
f Complementary = (90 − q)°, 
supplementary = (180 − q)° 
g Complementary = (40 − n)°, 
supplementary = (130 − n)° 
h Complementary = (100 − k)°, 
supplementary = (190 − k)° 
i Complementary = (70 + p)°, 
supplementary = (160 + p)° 
j Complementary = x°, supplementary = (90 + x)° 
4 a x = 50° b x = 20° 
c x = 160°, y = 20°, z = 160° 
d x = 90°, y = 72° e x = 40° f x = 160° 
g x = 40° h x = 330° i x = 85° 
j x = 30° k x = 20° l m = 45° 
5 a Corresponding b Alternate 
c Alternate d Co-interior 
e Alternate f Corresponding 
6 a p = 89° (alternate), q = 89° (vertically opposite p) 
b i = 120° (corresponding) 
c h = 95° (co-interior) 
d a = 102° (straight), b = 78° (vertically 
opposite), c = e = 78° (corresponding to 78°), 
d = f = 78° (corresponding to b) 
e x = 65° (co-interior), n = 115° (alternate), 
m = 115° (alternate), y = 65° (co-interior) 
f m + 40° = 70° (alternate), m = 30° 
g x + 60° = 80° (corresponding), x = 20° 
h 3x = 120° (corresponding), x = 40° 
i 4m = 80° (co-interior), m = 20° 
7 a Parallel (corresponding angles are equal) 
b Not parallel (co-interior angles are not 
supplementary) 
c Not parallel (alternate angles are not equal) 
d Not parallel (corresponding angles are not equal) 
8 Roof a as corresponding angles are equal, making 
the rafters parallel. 
9 a 85° b 25° c 45° d 30° 
e 75° f 48° g 20° 
h a = b = c = 60° i j = 75°, k = 52.5° 
10 a m = 106° b t = 110° c k = 65° 
d q = 122°, s = 31° 
e t = 105°, m = 75° 
f p = 64°, q = 116°, r = 64° 
11 a x = 60° b x = 45° c x = 80° 
d x = 30° e x = 50° f x = 27° 
Exercise 3B — Other polygons 
1 a 1080° b 900° c 1800° 
2 a i 540° ii b = 120° b i 720° ii c = 130° 
c i 900° ii d = 30° d i 720° ii h = 80° 
3 a Yes: all sides equal, all angles equal 
b No: not all sides equal 
c Yes: all sides equal, all angles equal 
d Yes: all sides equal, all angles equal 
e No: not all angles equal 
f Yes: all sides equal, all angles equal 
4 a t = 60° b p = 108° c a = 135° d t = 150° 
5 a Square b Equilateral triangle 
6 120° 
7 135° 
8 a Dodecagon b 1800° 
9 156° 
10 168° 
11 a 120° b 60° c 360° 
12 a 108° b 72° c 360° 
d The sum of the exterior angles is again 360°. 
13 45° 
1 
a 
-- 1 
k4 ---- 2 
m4 ------ 42 
y5 -----
A n swe r s 629 
answers ➔ 
14 24 sides 
15 No, it is not possible to have a shape with sides. 
16 30° 
Exercise 3C — Constructing triangles 
1 to 3 Check with your teacher. 
4 c i 
5 c iii 
6 Check with your teacher. 
7 a b 
c d 
e f 
8 4 triangles 
9 2 triangles 
10 
10 Quick Questions 1 
1 x = 24° 
2 Parallelogram 
3 Check with your teacher. 
4 Check with your teacher. 
5 C 6 C 7 A 
8 True 9 36° 
10 Interior 150°; exterior 30° 
Maths Quest challenge (page 101) 
1 150° 2 36° 
Exercise 3D — Further sketching and 
constructing 
1 2 
3.5 cm 3.4 cm 
50° 
3 4 
It is a right-angled triangle. 
5 
6 a An equilateral triangle: i Set the compasses to a 
desired length and, from a point at the beginning 
of a baseline, draw an arc. ii Then, using the same 
radius, and using the point of intersection of the 
line and the arc, draw another arc. iii Join each 
pair of points; that is, the starting point, the point 
where the line and the arc meet and the point 
where the two arcs meet, by straight lines. 
b i Draw a 4 cm line. Set the compasses at 2 cm and 
draw arcs from both ends of the line. ii Using a 
protractor, construct 120° angles at both ends of 
the line. iii Draw a line at this angle to intersect 
the arc at each end. iv Join the points of 
intersections of the arcs and the arms joining the 
angles by a straight line. 
7 In a triangle, the sum of the two smaller sides needs 
to be more than the largest side. 
a The sum of the two smaller sides is less than the 
largest side. 
b The sum of the two smaller sides is equal to the 
largest side. 
c The largest side must be opposite the largest 
angle. 
8 b Altitudes 
9 Tangent 
10 Decagon 
11 to 16 Check with your teacher. 
Maths Quest challenge (page 108) 
11 pieces 
One possible solution: 
10 Quick Questions 2 
1 x = 53°, y = 53° 2 y = 172° 
3 y = 120° 4 m = 140° 
5 u = 10°, v = 100°, w = 100°, x = 80°, y = 100°, 
z = 80° 
6 x = 58° 7 x = 45° 
8 x = 120° 9 x = 122° 
10 a D b A, D c A 
Exercise 3E — Constructing polygons 
1 Perpendicular bisectors meet outside the triangle. 
2 Perpendicular bisectors meet on the hypotenuse. 
3 Construct the perpendicular bisector of the base; 
vary the radius to get different triangles. 
4 Answers will vary. 
5 
6 and 7 Answers will vary. 
8 Find the angle bisectors of the angles formed at the centre 
of the circle. Join them to the circumference to create 12 
vertices. Join the 12 vertices to create the dodecagon. 
9 and 10 Constructions 
360 
23 
-------- 
A 
B C D A 
B 
C D 
Q 
P 
S 
R 
M 
N 
L M 
P 
S 
R 
M 
T U 
D 
R 
E F 
M 
P 
R Q 
5 cm 7 cm 
8 cm 
C 
A 
B 
6 cm 
10 cm 
8 cm 
L 
7 cm 
48° 
M N 
9 cm 
V W 
X 
U 
3.5 cm 
2.5 cm 
5 cm 
4 cm 
5.1 cm 
3A 
3E
630 A n swe r s 
answers 
11 Create perpendicular bisectors, then angle bisectors to 
create 45° angles from the centre of circle, and a diameter. 
Exercise 3F — Geometry in 
architecture, design and art 
1 2C 3 D 
4 Figure a, tall adult; figure b, short child 
5 Construction 6 Approximately 1.6 to 1 
7 a b − a b -- c 
----------- 
a 
d b2 − ab − a2 = 0 
e = ------------------- 
(disregard negative value for b) 
f ---------------- 
, approximately 1.618 
8 a Long side = 6.472 b Short side = 2.472 
c Long side = 18.171 d Short side = 309.326 
9 a Regular triangle, square 
b 3, 3, 3, 4, 4 and 3, 3, 3, 3, 3, 3; irregular 
10 
Summary 
1 smaller than 2 obtuse 
3 180º 4 reflex 
5 transversal 6 adjacent 
7 360° 8 number of sides 
9 divide 10 regular 
11 pair of compasses 12 protractor 
13 exterior 14 bisector 
15 perpendicular 16 sketching 
17 circumcentre 18 vertex 
19 alternate 20 Tessellations 
Chapter review 
1 a 60° b 50° 
c a = 120°, z = 60° d a = 60°, c = 60° 
e f = 80°, d = 80° f g = 70°, h = 70°, j = 110° 
g 75° h 40° i 10° 
2 a x = 83°, y = 97° b x = 70° 
c x = 60° d x = 50° 
e x = 20° f m = 35° 
g x = 107° h x = 75°, y = 25° 
i x = 280° 
3 a 540° b 1080° 
4 a x = 110° b m = 50° c m = 45° 
5 Check with your teacher. 
6 Make a 60° angle, bisect it, then bisect one of the 
smaller (30°) angles. 
7 Make a straight angle, then a 60° angle, then bisect 
the 60° angle. Its supplement is 150°. 
8 a 
b Angle subtended by each side at centre = 36° 
9 There are 10 differently shaped triangles. 
10 C 
11 p = 108° 12 B 13 B 
Chapter 4 Algebraic expressions 
and relationships 
Are you ready? 
1 a 6 + 4 b 2 × 5 c 7 − 3 
2 a D b E c A 
d B e C 
3 a 3a, −4a, a b 5x, x, x 
c 7qp, 7pq d ac, 2ac 
4 a 13y b 3n + 4m 
c 7x + 4 d 9k + 2p 
5 a 12x b 21ab 
c −5kp d 6m2n 
6 a 3x b 15 
c 4 d −7xy 
7 a 2x + 6 b 3y − 3k 
c −5m − 10 d −7a + 28 
8 a 18 b −15 c −3 
d 9 e 25 f 80 
g 60 h 2 
Exercise 4A — Generalised arithmetic 
1 a 3 b 7 c −2 d −8 e 1 
f −1 g h i − j − 
2 a 6 b 7 c 3 d −2 e 3 
f −2 g −7 h −11 i − j 
k 1 l 0 
3 a i 3 ii 5 iii 8 iv 5x2 
b i 3 ii −9 iii −6 iv −9m2 
c i 4 ii 5 iii 5 iv −7x2 
d i 4 ii 9 iii 4 iv −9b2 
e i 5 ii 11 iii −4 iv −7q 
f i 5 ii −9 iii 5 iv −9p 
g i 4 ii 4 iii −2 iv −3ac 
h i 5 ii 5 iii 9 iv −3u 
i i 5 ii −1 iii 8 iv −m 
j i 5 ii 7 iii 14 iv −3cd2 
b 
a 
b – a 
b 
a + 5a 
2 
1 + 5 
2 
Five different 
triangles 
Three different 
triangles 
1 
2 
-- 
-- 1 
-- 1 
-- 1 
1 
3 
2 
4 
-- 
9 
2 
3 
-- 1 
-- 
4
A n swe r s 631 
answers ➔ 
4 a p + 2 b q − 7 c 3p + 2 d 9q − 7 
e 10 − 4p f 5 − 2p g p + q h p − q 
i 3p + q j p − 2q k pq l 4pq 
m + 3q 
2p 3q n 2q − 3p o ------ p 
------ 
5 a B b D c A d B 
6 a 11 b x + 5 c y + 5 
7 a 3.5 km b (x + 2) km 
8 a 4 b 2.5 + t c 2.5 − y 
9 a 10n, where n = number of shirts 
b N + 30, where N = Nick’s dollars 
c 7g − 4, where g = goals scored 
10 a i 94 ii 6x + y b i 66 ii 6p + q 
c i 28 ii 6x + y − 6p − q 
11 xy dollars 12 cents worth of chips 
13 a b 
------ 
30 – d 
4 
14 a (30 − d) cm b cm 
c cm 
----------------------- 
x 
4 
-- x 
-- x 
15 a b c − 
-- 
-------------- 24 – c 
16 a hours b (c + -------------- 
) hours 
17 a 1 b 8.30 pm and 9.30 pm c 5 d 24 
e 7.30 pm and 8.00 pm 
f None of Marty’s friends left and then returned, 
and also nobody arrived who hadn’t been invited. 
Exercise 4B — Simplifying algebraic 
expressions 
1 a 9ab, −ab b 4x 
c −3za, −az d 2x2, −x2 
e −2x2y f −x2y5, −3x2y5 
g p3x2w5, −5x2p3w5 h 4y5z4x2, −2x2z4y5 
2 a 7x b 11y c 19m d 11q e 8r 
f 5x g 8a h 8y i 13x j 16p 
k 9q2 l 3x2 m 8x2 − 3y 
n 2m2 + 2n o 7x2 + x 
p 9h2 + h + 9 q −2g2 + g − 12 r −5m2 + m + 15 
s 12a2 + b + 4b2 t 3m + 7n2 u 12xy + 2y2 
v 2ab + 5a2b w 16x2y − 3xy x m2n + 11n 
y −3xy + 9x2 z 8m2n + 5mn2 
3 a B b D c A d D 
4 a 6mn b 20xy c 8pq d −10xy 
e −12xy f 15mn g 10a2 h 20y2 
i 5p2 j 7m2 k 6mnp l −6ab2 
m 10m2n n −18a2b o 30x3y2 p −12p2q3 
q −56c3d r 30a4b7 
5 a 3x b 3m c 2y d 4m e 4m 
f 2x g −7x h −4m i j 
-- 
----- 1 
------- 1 
k l m n o 2yz 
----- 7yz 
p q r − 
6 a 40x2y2 b 56ax2y2 c 12x3y2 
d e− ------ 
f 2 
g 40a3b2 h −8a3b3 i 16a4 
Maths Quest challenge (page 141) 
1 21x + 23y, 34x + 37y, 55x + 60y 
2 Hint: Let n represent the number of the month and d 
represent the day of the month. Form an algebraic 
expression from the instructions given. Show how 
this becomes 100n + d. 
10 Quick Questions 1 
1 12 2 550 − y 
3 4 + t 4 (100 − q) cm 
5 B 6 + 
7 5x2 + 7x 8 12x2 + 2y 
9 6x3 10 4r2 
Exercise 4C — Expanding to remove 
grouping symbols 
1 a 3x + 6 b 4x + 12 c 5m + 20 
d 2p + 10 e 4x + 4 f 7x − 7 
g −4y − 24 h −5a − 5 i −3p + 6 
j −x + 1 k −x − 3 l −x + 2 
m 6b − 12 n 24m − 16 o −30m + 24 
p −27p + 15 
2 a x2 + 2x b y2 + 3y c a2 + 5a 
d c2 + 4c e 4x + x2 f 5y + y2 
g 7m − m2 h 8q − q2 i 2xy + 4x 
j 5pq + 20p k −3xy − 12y l −10pq − 90p 
m −3b + ab n −35m + 7mn o −30a + 18a2 
p −28x + 16x2 
3 a 2p − 2 b 5x − 17 c −7p − 17 
d −12p + 3 e 6x2 − 20x f 2m2 + 7m 
g 3px + 6x − 5 h 4y2 − 4y + 7 i −4p2 + 13p 
j 4x − 13y k 2m2 − 8m − 4 
l −3p2 + 10pq − 1 m −30a + 10ab 
n 7cd − 12c2 − 5c o −2p − 17 
p 3 − 3m 
Exercise 4D — Simplifying expressions 
with grouping symbols 
1 a 8x + y b 10p + 8q 
c 18a + 29b d 19c + 22d 
e 2m − 11n f 6x − 11y 
g 9x + 5y h −14p − 8q 
i −4a + 3b j 4x − y 
k 5p − 10q l −8c + 9d 
m 13x − 19y n −7p + 11q 
o −5a + 3b p 8c + d 
2 a 2ab + 2a − 3b b 2xy + 4x − 2y 
c 2cd + 3c d 2pq − 2p 
e 5cd − 11c f 5ab − 21a − 3b 
g 5m h 6cd − 36c 
i 6m2 + 6m − 10 j 9cd − 8c 
k −15a2 + 2b2 − 9ab l −8c2 + 3d2 + 22cd 
m 12m2 − 20m − 4 n 2p2 + 7p − 6 
o −7x2 + 41x − 6 p −10y2 − 6y − 12 
3 a B b A c D 
p 
2q 
p 
x 
y 
-- 
x 
n 
-- x 
2n 
-------------- 
3(30 – d) 
4 
-- x 
6 
4 
6 
24 – c 
7 
7 
m 
2 
---- x 
3 
4m 
9 
------- 4x 
3 
5m 
------ 
2a 
35ab 
2 
------------ xy 
4 
-------- 
11 
x2 
2y 
----- 5a 
4b 
x 
3 
-- x 
-- 
5 
3F 
4D
632 A n swe r s 
answers 
Exercise 4E — Algebraic fractions 
1 a b -- c − m 
d e 
-- 9m 
---- x 
--- 17q 
--------- p 
--------- x 
f g h − i j 
--------- 25 
------- 7 
-------- 11 
------ 11 
2 a – b c – d e 
f 
------- 
-- 
-------- 
------ b 
3 a 3ab b c d e 3 
------- 1 
----- n 
f g h i 14 j 
-- 4m 
------- 2q 
------ 1 
k l m n o 
-- 
-- 
4 a 3ab b 2x c d ------ 
e 3 
------ 7b5 
----- 3a 
-- 3 
f g 4 h i j 
-- x3 
------ 1 
------ 3q 
k l m n o 
10 Quick Questions 2 
1 5m + 4n 2 6 − x 
3 (60 − p) cm 4 4y2 − 2y + 2 
5 8mn 6 
7 86yz 
-------- 
----- 
9 10 
Exercise 4F — Substitution and 
formulas 
1 a 7 b −40 c 7 
2 a 32 volts b 250 volts c 240 volts 
d 245 volts 
3 a 15 b 10 c 18 d 45 e 30 
f 10.72 g 21 h 22.4 i 50 j 171 
k 4 l −30 m 32.75 n 38.33 o 34.54 
4 a i 12 cm2 ii 5 cm2 iii 1.5 cm2 
b i 15 ii 6 iii 0 
c i 5 ii 13 iii 10 
d i 63 cm3 ii 580 cm3 iii 8.28 cm3 
e i 10 ii 15 iii 20 
f i 19.44 ii 32.4 iii 10 
g i 461.58 ii 69 360.09 iii 78.11 
h i 1670.48 ii 150.72 iii 226.33 
History of mathematics 
1 Heron invented machines and toys such as fountains, 
syphons and steam engines which were operated by 
water, steam or compressed air. 
2 It works out the area of a triangle using the side 
lengths of the triangle. 
3 He was a mathematician and astronomer in India. 
4 It works out the maximum area of a quadrilateral 
using the side lengths. 
5 Heron’s formula is the same as Brahmagupta’s with 
one of the side lengths set to 0. 
Summary 
1 term 2 coefficient 
3 pronumeral 4 equation 
5 like 6 10x − y 
7 worded question 8 like terms 
9 inside 10 collect like terms 
11 10x + 6 
12 lowest common denominator 
13 denominators, cancelling 
14 multiplication, reciprocal 
15 substitute 
Chapter review 
1 a i 4 ii −8 iii −5 iv −8xy2 
b i y + 8 ii x − y iii x + y iv 7xy 
v 5y − 2x 
2 a xy dollars b i (24 − k) m ii m 
3 a 17p b 10m2 c y2 + 2y 
d 10ab + 3b2 e −3s2t f 4x + 9xy 
g 16c2d − 2cd h 5x2y − 6 i n2 − 4p2q + 6 
j 15ab − 3a2b2 
4 a 12ab b −5y2 c 2ab2 d 6p2q e 8x2y2 
------- 9 
-- 1 
------ 1 
f 5a g h i j 
5 a 5x + 15 b −y − 5 c −3x + 2x2 
d −8m2 − 4m 
-- 
6 a 3x + 3 b −10m − 1 c 4m2 − 9m − 5 
d 4p − 6 
7 a 9a + 8b b −5x − 18y c 11m − mn 
d 4x2 − 10x + 3 
-- 31 
----- x 
8 a b c d ---------- 
e 2 
-- 2 
-- 2 
f g h i j 2 
-- 5 
-- x 
k l m n 
-- 
------ 
9 a 23 b 134 
10 a 307.72 cm3 b 5377.26 cm3 
Maths Quest challenge (page 160) 
1 Let D = dark coloured counter, L = light coloured 
counter, S = empty space so starting position is 
DDSLL. 
Solution is: DDLSL, DSLDL, SDLDL, LDSDL, 
LDLDS, LDLSD, LSLDD, LLSDD 
2 Possible solution is DDDLSLL, DDSLDLL, 
DSDLDLL, DLDSDLL, DLDLDSL, DLDLDLS, 
DLDLSLD, DLSLDLD, SLDLDLD, LSDLDLD, 
LLDSDLD, LLDLDSD, LLDLSDD, LLSLDDD, 
LLLSDDD. 
7x 
12 
----- y 
6 
8 
4 
14 
2t 
15 
----- 13a 
10 
6 
15 
6 
1 
2 p 
10x 
4m 
20b 
18c 
10 + 12y 
15y2 --------------------- 
2x 
y 
----- q 
4 p 
5a2 -------- 
1 
3 
-- m 
12 
6m 
9 
8 
y 
-- 5 
3 
21 
45 
4 
1 
3y 
----- p 
4q 
1 
3 
10 
2 
4 
3m3 
5 
--------- 8b 
3c 
5 
2 
5y 
-- 
x 
8 
7x 
10 
----- 
23 
20b 
--------- 7z 
----- 
12 
2 
3 
-- 
24 – k 
3 
-------------- 
x 
3 
7m 
2b 
5 
7x 
10 
----- x 
12 
8 
24m 
1 
4 
-- 1 
4 
5 
3 
1 
6 
-- 3 
7 
6 
2b
A n swe r s 633 
answers ➔ 
Chapter 5 Linear equations and 
inequalities 
Are you ready? 
1 a x + 2 = 9 b 8x = 40 
c x − 11 = 3 d = 2 
2 a x = 6 b y = 13 
c k = 15 d x = −51 
3 a Yes b No 
c No d Yes 
4 a x = 3 b a = 6 
c m = 0 d y = −1 
5 a 6x − 12 b −2y − 2 
c 8a + 12 d −10p + 35 
6 a 
b 
c 
d 
7 a No b No 
c Yes d Yes 
8 a b = 4 b l = 13 
Exercise 5A — What is a linear 
equation? 
1 a, b, d, e, f, h, k, l 
2 a x + 3 = 5 b x − 9 = 7 c 7x = 24 
d = 11 e = −9 f 5x = −7 
g 14 − x = −3 h 3x + 5 = 8 i 2x − 12 = 15 
j = 5 
3 a B b D c B d B 
Maths Quest challenge (page 165) 
1 332 pages 
2 6 years ago 
Exercise 5B — Solving simple 
equations 
1 a x = 210 b x = 52 c x = 230 
d x = 23 e x = 142 f x = 96 
g x = 37 h x = 20 i x = 50 
j x = 138 k x = 442 l x = 243 
m y = −15 n y = 1.8 o y = 12.8 
p y = 2 q y = 24 r y = − 
s y = 21.5 t y = 172.5 u y = −8.32 
2 a x = 5 b x = −2 c x = 0.2 
d x = 1 e x = 1 f x = 2 
g x = 5 h x = −1 i x = 24.5 
j x = 1.2 k x = 22.25 l x = 
3 a x = 1 b x = −2 c x = 3 
d x = −6 e x = −1 f x = 
g x = 1 h x = –2.32 i x = 3 
j x = − k x = 1 l x = 3 
-- 1 
4 a y = −1 b y = 1 c y = 0 
----- 
d y = 5 e y = −8.6 f y = −0.9 
g y = 8.9 h y = 19 i y = −26 
j y = −1 k y = −1 l y = −1 
5 a x = −15 b x = 16 c x = −66 
d x = 12 e x = −3 f x = 4 
g x = 9 h x = −1 i x = 9 
j x = −2 k x = −7 l x = 
-- 1 
-- 
-- 2 
-- 
6 a z = 16 b z = 31 c z = −4 
d z = 6 e z = −9 f z = −6 
g z = −1.9 h z = 6.88 i z = 140 
j z = 0.6 k z = −35.4 l z = 8 
7 a x = 1 b x = 13 c x = −2 
d x = −8 e x = −4 f x = 30 
g x = −6 h x = − i x = 10.35 
j x = −0.046 k x = 22 l x = −5 
8 a x = 4 b x = c x = −1 
-- 
d x = −6 -- e x = ----- 
4 
f x = 8 
g x = −6 h x = 7.5 i x = 5.1 
j x = −6 k x = −5 l x = −61 
-- 
9 a C b D c C 
10 a a = −1 b b = 10 c c = 12.1 
d d = 4 e e = 5 f f = 12 
g g = 15.97 h h = 31 i i = 
j j = k k = −8 l l = 10.3 
Maths Quest challenge (page 173) 
1 5 days 2 4 3 30° 
10 Quick Questions 1 
1 x = −3 2 x = 5 
3 x = −12 4 x = 2.7 
5 x = 2 or 2.8 6 x = −42 
7 x = 5 or 5.25 8 x = 1.357 (to 3 dp) 
9 x = 7 10 x = 0 
Exercise 5C — Solving equations with 
pronumerals on both sides 
1 a y = −1 b y = 1 c y = −3 
d y = −5 e y = −45 f y = 
g y = −2 h y = 20 i y = 1 
j y = −1 k y = 4 l y = −2 
2 a C b A 
3 a x = 1 b x = −2 c x = 3 
d x = 4 e x = 9 f x = 3 
g x = −2 h x = 4 i x = −4 
j x = k x = 0 l x = − 
x 
6 
-- 
–5 –4 –3 –2 –1 0 1 2 3 4 5 
x 
x  2 
x  5 
–4 –3 –2 –1 0 1 2 3 4 5 6 
x 
x  0 
–5 –4 –3 –2 –1 0 1 2 3 4 5 
x 
x  –1 
–5 –4 –3 –2 –1 0 1 2 3 4 5 
x 
x 
5 
-- x 
-- 
2 
3x 
2 
----- 
-- 1 
1 
3 
----- 
18 
-- 2 
1 
3 
-- 
3 
383 
600 
-------- 
1 
2 
-- 
2 
3 
-- 
5 
6 
-- 1 
4 
13 
1 
5 
3 
1 
4 
3 
1 
2 
-- 
7 
10 
----- 
3 
7 
-- 1 
7 
2 
3 
45 
13 
15 
----- 3 
7 
13 
226 
-------- 
1 
6 
-- 
1 
6 
-- 
4 
5 
-- 
1 
4 
-- 
8 
27 
----- 
1 
5 
-- 
1 
2 
-- 4E 
-- 3 
4 
5C
634 A n swe r s 
answers 
4 a x = −6 b x = 7 c x = 2 
d x = −2 e x = 13 f x = −7 
g x = -- h x = − ----- 
2 
i x = 1 
5 a D b C 
Maths Quest challenge (page 175) 
1 kg or approx. 667 g 
2 4 
Exercise 5D — Solving linear equations 
with grouping symbols 
1 a x = 6 b x = –3 c x = 0 
d x = 56 e x = 1 f x = 0 
g x = −1 h x = −2 i x = 6 
j x = 0 k x = −0.8 l x = 6 
2 a b = 1 -- b m = 4 -- 1 
c a = −1 
1 
-- 
d m = −1 -- e p = -- 3 
f m = 2 
-- 
2 
g a = −1 h p = 1 -- i a = 3 
1 
-- 
j m = −2 -- k a = − -- 1 
l m = − 
1 
-- 
3 a x = 16 b x = 2 c a = 5 
d b = 7 e y = 7 f x = −3 
g m = 4 h y = 1 i a = 5 
j p = −2 k m = 3 l p = 1 
4 a y = −7.5 b y = −4.667 c y = −26.25 
d y = 8.571 e y = −2.9 f y = 3.243 
g y = 3.667 h y = 2.75 i y = 1.976 
j y = −2 k y = −3.167 l y = 1.98 
5 a D b C 
6 a x = 5 b x = −3 c x = −8 
d x = −7 -- e x = 4 f x = 
----- 
10 
g x = −18 h x = 3 -- i x = 
2 
-- 
j x = −1 k x = 0 l x = −15 
Maths Quest challenge (page 177) 
1 27 2 6 
Exercise 5E — Solving problems with 
linear equations 
1 0 
2 60 years 
3 a 11.88 km 
b He will have to walk 1.12 km (1 km and 120 m). 
4 23 passengers 
5 a 0.06x b (1 − x) c 0.03(1 − x) 
d 0.06x + 0.03(1 − x) = 0.05 
e 0.667 or 66.7% 
6 947 
7 a Post quick distributor, cost = $700 
b 333 flyers, cost = $366.67 
8 24 km 
9 21 ≈ 21.9 km 
10 6, 7, 8, 9, or 10 books 
11 a 10 + 1.5(x − 3) + 1(x − 6) 
b Check with your teacher. 
c Mississippi.com is $4.50 more expensive. 
d 14 books 
10 Quick Questions 2 
1 x = −92 2 x = 
3 x = −3 4 x = 28 
5 x = −4 6 x = −16 
7 x = 3 8 0.156 
9 46 10 118 
Exercise 5F — Solving more complex 
equations 
1 a x = b x = 3 c x = d x = −7 
e x = −2 f x = g x = −5 h x = 5 
i x = −2 j x = −2 k x = 2 l x = −6 
2 a x = b x = 15 c x = −6 d x = − 
e x = −1 f x = −192 g x = h x = 12 
i x = 3 j x = 3 k x = 52 l x = 1 
3 a x = b x = 1 c x = 4 d x = −3 
e x = 5 f x = −1 g x = 1 h x = −4 
i x = 1.5 j x = −4 k x = 3 l x = 1 
4 a B b A 
Exercise 5G — Solving linear 
inequalities 
1 a x  2 b a  −1 c y ≥ 7 
d m ≥ 4 e p  1 f x  7 
g m ≤ 9 h a ≤ 7 i x  3 
j m ≥ 2 k q ≥ −4 l a  −8 
2 a m  3 b p ≤ 2 c a  4 
d x ≥ 5 e p  −5 f x ≤ −7 
g m ≥ −0.5 h b  −0.5 i m  18 
j x  8 k a ≤ –14 l m ≥ 25 
3 a m  4.5 b x ≥ 3 c p  4 
d n ≤ 2 e b  5 f y  2 
g m ≤ −1 h a ≥ −5 i b  −4 
j c ≤ −1 k p  −2 l a ≥ −7 
4 a m  3 b a ≥ 2 c a  −1 
d a ≤ −3 e x  6 f x ≤ 2 
g b  4 h a  5 i m  2 
j m ≤ 3 k b ≤ −1 l m ≥ 1 
5 a x ≤ 7 b x ≥ −18 c x  −10 
d x  10 e x ≥ 5 f x  −1 
6 a m  −2 b p ≥ −3 c a ≤ 5 
d p ≥ −5 e y ≤ −3 f x  7 
g p  0 h a ≥ i x  –3 
j a ≤ −11 k b ≤ 3 l x  −3 
m k  8 n x  −18 o a ≤ 40 
7 B 
8 a x  −1 b m ≤ −3 c x  17 
d a  e m ≥ 1 f m ≥ −12 
1 
6 
17 
2 
3 
-- 
1 
6 
2 
2 
1 
3 
5 
3 
1 
2 
-- 1 
2 
3 
1 
2 
6 
4 
1 
9 
-- 
1 
3 
-- 
1 
2 
11 
2 
3 
3 
3 
7 
-- 
123 
137 
-------- 
5 
11 
----- 
5 
9 
-- 
-- 29 
----- 5 
20 
31 
8 
----- 
36 
----- 3 
----- 10 
8 
11 
43 
-- 
4 
11 
12 
----- 
5 
17 
----- 2 
-- 10 
9 
----- 
19 
1 
2 
-- 4 
-- 
7 
1 
4 
-- 5 
-- 
8 
----- 15 
----- 11 
----- 31 
5 
19 
58 
14 
----- 
17 
----- 9 
----- 2 
----- 10 
20 
43 
13 
61 
----- 
26 
1 
3 
-- 
1 
3 
-- 
5 
11 
----- 
1 
2 
-- 4 
-- 
5 
1 
5 
-- 
1 
2 
-- 
5 
8 
-- 1 
-- 
3
A n swe r s 635 
answers ➔ 
9 a k  2 b a  −5 c m ≤ 1 
d x  5 e y ≥ 7 f d  −2 
g p ≥ − h x ≥ −5 i m  −2 
j a  9 k p ≥ 3 l x  −4 
Exercise 5H — Rearranging formulas 
1 a = -- b = ----------- y – b 
y + b 
x x c x = 
-------------- 1 
d x = e x = f x = 
----------- 
----------- 
----------- 4y + 1 
g x = h x = i x = −5y − 12 
--------------- 
5a – 9 
19 
j x = 12a k x = l x = 
------ 5( f – 32) 
2 a P = b c = c c = 
--------------------- 
----------------------- 
----------- b2 – d 
--- v – u 
d I = e t = f c = 
g y = hm + k h y = m(x − b) + a 
i a = y − m(x − b) j x = k r = 
-------------- 
------------------------- C 
--------------- 2(s – ut) 
l x = m a = n G = 
3 500 km 
4 
Maths Quest challenge (page 195) 
1 51 2 9 3 17 
Summary 
1 pronumeral, equals sign, one 
2 left-hand side 3 by itself 
4 reverse order 5 cross-multiply 
6 single 7 expand 
8 portion 9 reversed 
10 subject 
11 formula, other pronumerals 
Chapter review 
1 b, c, f, g, i 
2 a 2x = 3 − x b 3x + 8 = 19 c 6x = 4 
d − 1 = -- 
e 7(2x + 5) = 0 
f 2x = 100 + x + 50 
3 a y = 13 b y = 19 c y = 22 
d y = −1 e a = −12.8 f a = 0.9 
g a = 2.8 h a = −0.6 i b = −2.52 
j b = 3.1 k b = −3.45 l b = 0.749 
4 a x = 2 b x = −2 c x = 4 
--------- 
d x = −21 e x = 3 f x = 18 
g x = −2 h x = 15 i x = 19 
j x = 13 k x = −6 -- l x = 1 
1 
m x = 6 n x = −8 o x = −11.13 
5 a x = −2 b x = −1 c x = 
d x = 3 e x = 3 f x = 5 
g x = 2 h x = −1 i x = 7 
6 a x = 3 b x = 2 c x = 1 
-- 1 
-- 
d x = −1 e x = −12 f x = −8 
-- 1 
7 a 8h + 21 = 45 b 3 hours 
8 600 km 
9 a x = b x = 6 c x = − 
-- 3 
d x = 1 e x = 12 f x = 1 
10 a x = b x = 22 -- 
c x = 2 
d x = 5 e x = 3 f x = − 
----- 
-- 
-- 16 
----- 
11 a x  4 b x ≥ c x  −2 
d x  −14 e x ≤ −2 f x  −1 
g x ≥ 24 h x  −8 i x  − 
j x ≥ k x ≤ −7 l x  −1 
m x ≤ −3 n x ≤ −4 o x  
p x ≤ 7 q x  −10 r x ≥ 1 
-- 
-- 2 
-- 
-- 
----- 
----------- q – 2r 
12 a x = b x = c P = + 1 
----------- 2s 
d w = e a = f t = 
-------------- 
g a = h b = 
Chapter 6 Surds 
Are you ready? 
1 a b c 
2 a 0.8 b 0.375 c 0.8875 
3 a b 12.7 c 
4 a b c 
5 a 8 b 5 c 3 
d 2 e 3 f 1 
6 a 2.45 b 0.3 c 7.105 
d 0.71 e 15.290 f 73.1 
7 a 4x − 32 b 6x + 3 c −20x − 45 
8 a x2 − 49 b 3x2 − x − 10 
c 4x2 − 12x + 9 
Exercise 6A — Rational numbers 
1 a 0.75 b 0.4 c 0.9 d 0.625 
e 0.66 f 0.275 g 0.9125 h 0.3125 
i 0.52 j 0.45 k 0.57 l 0.08 
2 a b c 
d e f 
g h 
3 a b c 
d e f 
g h i 
j k l 
2 
3 
-- 
6 
7 
-- 
1 
2 
-- 
y 
a 
a 
2a 
y + 7 
2 
----------- 8 – 6y 
5 
y – 2 
y + 1 
y – 2 
5 
--------------- 14a + 13 
93 
g + 3 
4 
------------ 5 f 
9 
9 
V 
R 
a 
4a 
y – a + mb 
m 
2π ------ 
f – by 
a 
t2 --------------------- Fr2 
Mm 
50 4π –π 
------------------ ≈ 11.92 cm 
10 
x 
----- x 
6 
1 
2 
-- 
3 
4 
-- 1 
-- 
5 
1 
3 
-- 
5 
2 
3 
-- 
1 
2 
-- 
1 
5 
-- 5 
7 
4 
5 
12 
----- 1 
2 
2 
1 
2 
-- 1 
5 
14 
2 
9 
-- 1 
6 
6 
7 
-- 1 
2 
3 
8 
21 
5 
6 
-- 
1 
5 
-- 
1 
3 
5 
2 
5 
-- 1 
2 
1 
2 
-- 7 
12 
y + 4 
6 
----------- y – c 
m 
2 
P – 2l 
2 
-------------- v – u 
t 
u + v ----------- 
v2 – u2 
2s 
---------------- ------------------- 
2A – ah 
h 
----- 6 
-- 5 
2 
9 
12 
-- 
7 
0.35 5.14-- 3 
----- 7 
-- 
5 
5 
20 
8 
˙ 
2 ˙ 
7 0.3 ˙ 
0.16 ˙ 
0.32 
0.785 ˙ 
0.594 0.125 125 1 
0.375 46 0.814 35 
0.6 ˙ 
0.27 0.8 ˙ 
0.27 ˙ 
0.83 ˙ 
0.142 857 
0.916 ˙ 
0.06 ˙ 
0.90 
0.2916 ˙ 
0.56 ˙ 
0.259 5D 
6A
636 A n swe r s 
answers 
4 a B b D c C d C e D 
5 a -- b ----- 3 
c ----- 7 
d -------- 67 
e 
19 
----- 
f g h i j 
k l 
6 a b c d e 
f g h i j 
k l 
7 a C b A c C d D 
History of mathematics — Richard 
Dedekind 
1 Carl Gauss 
2 Dedekind cuts 
3 Writings on the work of other mathematicians 
Exercise 6B — Irrational numbers 
1 a Surd b Not a surd c Not a surd 
----- 357 
-- 27 
----- 7 
-- 3 
----------- 
-------- 29 
----- 
----- 7 
----- 71 
-- 28 
-- 2 
----- 
-------- 379 
----- 109 
----- 5 
----- 17 
-------- 
-------- 725 
-------- 
d Surd e Surd f Surd 
g Not a surd h Not a surd i Surd 
j Not a surd k Surd l Not a surd 
2 a C b D c A d D e D 
3 a Rational b Irrational c Rational 
d Rational e Rational f Rational 
g Rational h Rational i Rational 
j Irrational k Rational l Irrational 
4 a 8.185 b 9.055 c 12.124 d 2.285 
e 2.627 f 0.868 g 50.339 h 44.294 
i 24.653 j 94.526 k 3.473 l 18.846 
5 a 2.844 b −9.637 c 4.019 d 5.983 
e 5.059 f 1.052 g 1.424 h −3.363 
i −2.431 j 0.9422 
6 a 23 b 15 c 15 d −13 e 10 
7 a A b C c D d C 
8 a 56.37 b −9.48 c −1.05 d 0.51 
e 28.08 f 2.02 
9 a Rali’s answer is approximate, Tig’s answer is 
exact, so the teacher is right. 
b c 
-------- 
d Rali: 39600, Tig: 40 000 
e 400 
f The difference between and 0.33 is only , 
but has much more significance if taken over a 
larger amount. 
10 a cm or cm b 14.1 cm 
11 or approximately 4.9 m 
Maths Quest challenge (p. 208) 
1 A recurring decimal has a pattern of numbers that 
recur. We can multiply the decimal by a power of ten, 
like 10, 100, 1000 …, and shift the pattern before the 
decimal point. Subtracting leaves just the whole 
numbers and then by division the decimal is 
expressed as a fraction with q ≠ 0 (refer to worked 
example 2 on page 202). 
2 Squaring both sides gives 2 = . So p2 = 2q2. But 
this implies p2 is divisible by 2, therefore p must be 
divisible by 2. Let p = 2m. Now p2 = 4m2. Therefore 
q2 = 2m2. This implies that q2 is divisible by 2. 
2m 
Therefore let q = 2n. Now --- = ------- 
. This contradicts 
our assumption that was in simplest form. 
Therefore, cannot be a rational number, therefore 
is irrational. 
10 Quick Questions 1 
1 0.325 2 3 4 
5 6 Rational 7 Rational 
8 Irrational 9 Rational 10 Irrational 
Exercise 6C — Simplifying surds 
1 a b c d 7 e 
f g h i j 
k l m n o 
p q r s t 
2 a b c 48 d e 
f g h i j 
3 a b c d e 
f g h i j 
4 a D b A c C d C e D 
f D g D h B 
5 a b c d e 
f g h 
6 a m b m c ≈ 6.804 m 
7 a cm b 224 cm 
Exercise 6D — Addition and 
subtraction of surds 
1 a b c 
d 0 e f 
g h i 
j k l 
m n o 
p q r 2 
2 a b 0 c d 
e f 
g h 
i j 
k l 
m n 
3 a D b A c C d A 
4 
5 
10 
50 
100 
20 
3 
4 
25 
8 
40 
1000 
221 
250 
80 
5 
9 
3 
33 
99 
15 
2 
11 
90 
18 
300 
990 
616 
999 
999 
33 
100 
-------- 1 
300 
1 
3 
-- 0.003 ˙ 
200 10 2 
2 6 
p 
q 
--- 
p2 
q2 ----- 
p 
q 
2n 
p 
q 
--- 
2 
2 
0.16 ˙ 
-- 7 
5 
8 
-- 
9 
127 
495 
-------- 
2 5 2 2 3 2 30 
5 2 2 7 6 3 12 2 4 3 
10 5 9 2 2 13 55 2 21 
7 2 11 3 7 7 78 4 10 
4 2 15 3 35 2 20 6 
10 3 4 42 72 2 27 5 132 2 
12 175 108 80 384 
90 32 720 600 338 
15 3 19 5 16 7 17 2 a c 
d2 b hk j f f 
3 2 3 3 12 – 3 3 
60 14 
2 2 –4 5 –6 3 
5 11 2 7 
10 2 + 7 3 8 5 + 6 8 10 + 7 3 
16 2 – 11 5 2 6 5 5 + 15 
8 7 – 11 11 – 2 7 – 13 
3 6 – 4 3 5 2 – 6 7 
2 –5 3 –4 7 
5 6 + 6 5 2 3 – 3 5 
4 6 + 6 5 – 14 2 29 5 + 22 3 
9 11 – 30 28 2 – 39 5 
69 3 – 17 2 18 10 + 42 2 
69 – 51 2 41 5 + 6 3 – 6 2
A n swe r s 637 
answers ➔ 
4( ) cm 
5 a 67 m b m 
c m d 10.39 m 
Exercise 6E — Multiplication and 
division of surds 
1 a b 5 c −5 d 
e f 8 g −10 h 
i j k l 24 
m −150 n o −168 p 
q 1250 r s t 
u 
2 a D b C c A 
3 a b c d 
e f g h 4 
i j k l 
------ 1 
m n 15 o −8 p 
----- 3 
----- 13 
q 1 r 1 s t 
------ 
-- 
4 a B b C c C d D 
5 a 1 b 1 c 1 d 1 
6 a b c 
-- 3 
-- 1 
-- 1 
d e f 
g h i 
j k l 
m 12 n o 
p −15 q r 
7 a 
b 
c −1 d 2 e 
f g h 
i 
-- 
8 a 42 b cm c cm 
d cm2 e 42 
9 ( + )2 = 2 + 2 + 3 = 5 + 2 
but ( )2 = 5 
10 a m b 
10 Quick Questions 2 
1 2.25 2 3 4 
5 4.05 6 2 7 8 
9 10 
Exercise 6F — Writing surd fractions 
with a rational denominator 
1 a ------ b ------ 5 
c ------ 6 
d 
7 
--------- 30 
e f g h 
--------- 30 
--------- 6 
------ 15 
2 a b c d 
------------- 3 10 
------------- 6 
e f g h 
--------- 70 
i j k l 
------ 
--------- 
--------- 
------ 
--------- 
------------- 2 6 
---------- 5 
3 a b c d 
4 a b c d 
5 a b 
6 a b 
c d 
e f or 5 − 
g 
h or 27 + 
Maths Quest challenge (p. 229) 
1 8, 18, 50 (other answers possible) 
2 a 177 768 889 b 399 9660 001 c 16 
Summary 
1 decimal 2 repeater 
3 rational 4 recurring 
5 power 6 fractions 
7 surds 8 approximation 
9 perfect 10 factor 
11 like 12 multiplied 
Chapter review 
1 a 0.08 b 0.8125 c d 
2 a C b D 
3 a b c d e 
4 a Rational b Rational c Irrational 
------ 
------ 2 3 
---------- 2 
------ --------- 
15 
------------------------------------------ 15 3 
-- 83 
-------- 5 
-- 83 
d Rational e Irrational f Rational 
----- 
5 = -- exactly but 15 
cannot be expressed as a 
fraction. 
6 a 7.9 b 13.7 c 0.5 d 25.7 
7 a b 51 cm 
8 a b c d 
9 A 
10 a b c d 
11 a b c 
12 D 
13 a b c 13 
d e3 f 
40 + 5 2 + 2 13 
(31 + 4 41) 
(36 – 4 41) 
5 5 35 
– 66 2 15 
2 14 6 2 15 2 
24 5 6 2 
108 2 1600 2 28 7 
12 15 
3 2 5 2 
15 3 5 
–2 5 9 3 –2 2 
2 
2 
------ 
3 
4 
6 
4 
45 
32 
4 
3 ---------- 
2 
5 
2 
3 
6 
2 
4 
3 2 + 3 5 5 6 – 5 2 6 5 + 6 11 
8 2 + 24 4 7 – 20 10 – 2 2 
42 + 7 7 6 + 15 2 5 + 2 10 
42 – 8 14 5 + 2 5 6 – 5 6 
60 – 18 5 12 14 + 8 35 
50 – 15 2 8 6 – 60 
2 10 – 15 + 2 6 – 3 
3 35 – 14 + 3 10 – 2 
7 + 10 
27 + 2 6 8 – 2 15 5 + 2 6 
42 – 24 3 
4 2 168 2 
504 2 
2 3 6 6 
5 
3 2 18 2 m2 
0.45 7 
----- 99 
11 
3 10 16 2 
40 2 
3 
3 
------ 
3 
3 
5 
6 
7 
10 
5 
--------- 5 
15 
5 
5 
15 
5 
6 
3 
5 
2 6 
3 
---------- 2 21 
7 
5 
2 
30 6 
30 
2 
2 
2 15 
7 
------------- 2 42 
3 
5 
4 
2 
2 
3 
2 
2 
3 2 
2 
---------- 2 
5(2 + 3) –2(1 – 2) 
4( 5 – 2) 3(3 + 7) 
3( 5 + 2) 5( 5 – 3) 15 
2( 7 + 2) 
3 6(3 6 + 5 2) 
2 
0.285 714 0.5 ˙ 
4 
5 
-- 8 
9 
100 
6 
99 
16 4 
1 
2599 
3 11 5 7 24 2 12 10 
150 180 605 18 
4 6 – 7 5 3 18 5 – 6 7 
5 2 24 21 
–2 6 1 
-- 
2 
30 
6 
--------- 6B 
6F
638 A n swe r s 
answers 
14 a 240 b 
73 – 40 3 
15 C 
16 B 
17 a ------ 7 
b 5 6 
c d 
14 
Chapter 7 Right-angled 
trigonometry 
Are you ready? 
1 a 30° b 58° 
2 a 4.74 b 18.5 c 0.378 
d 507.182 e 10.80 f 0.7643 
3 a x = 12 b x = 13.05 c x = 3.444 16 
4 a x = 24 b x = 0.36 c x = 540 
5 a 6.9 cm b 25.1 cm 
6 a Isosceles b ∠ABC = ∠ACB = 45° 
c 2.83 cm 
7 a East b South; west 
c C d B e Southwest 
Exercise 7A — Naming the sides of a 
right-angled triangle 
1 a b 
---------- 5 – 2 30 + 3 3 
6 
Adj. 
Hyp. 
Opp. 
θ 
c d 
Hyp. 
Adj. 
Opp. 
θ 
e f 
Opp. Hyp. 
Adj. 
Opp. 
Hyp. 
Adj. 
Opp. 
Opp. 
θ Hyp. 
Adj. 
θ 
2 a DE = hyp DF = opp ∠E = θ 
b GH = hyp HI = adj ∠H = θ 
c JL = hyp KL = opp ∠J = θ 
3 a 
Adj. 
θ 
Hyp. 
b ≈ 0.86 c ≈ 0.87 d ≈ 0.86 
4 a 
b 0.86 c 0.86 
5 a 
b 1 c 1 
6 D 
7 a D b A, C c C 
Maths Quest challenge (page 243) 
Exercise 7B — Trigonometric ratios 
1 a i sinθ = ii cosθ = iii tanθ = 
--- e 
--- d 
-- i 
-- h 
b i sinα = ii cosα = iii tanα = 
-- l 
-- j 
c i sinβ = ii cosβ = iii tanβ = 
---- n 
d i sinγ = ii cosγ = iii tanγ = 
-- b 
e i sinβ = ii cosβ = iii tanβ = 
-- v 
f i sinγ = ii cosγ = iii tanγ = 
2 a sinθ = b cosθ = c tanθ = 
----- 4 
----- 25 
d sin 15° = e tanθ = f cosα = 
----- 3.1 
g tanθ = h sin 35° = i sinα = 
3 a 
----- 14.3 
41° 
b O = 34 mm A = 39 mm H = 51 mm 
c i sin 41° = 0.67 ii cos 41° = 0.76 
iii tan 41° = 0.87 
d α = 49° 
e i sin 49° = 0.76 ii cos 49° = 0.67 
iii tan 49° = 1.15 
-- 
-- 
-- 
-- 
-- 
-- 
-- 
------- 
---------- 
f They are equal. 
g They are equal. 
h The sine of an angle is equal to the cosine of its 
complement angle. 
4 a 
25° 
b O = 23 mm A = 50 mm H = 55 mm 
Triangle Angle 
Opposite 
side 
Hypot-enuse 
θ 
Sine ratio 
i ΔMNO ∠M = 60° 26 mm 29 mm 0.86 
ii ΔPQR ∠P = 60° 30 mm 35 mm 0.86 
iii ΔSTU ∠S = 60° 18 mm 22 mm 0.86 
Triangle Angle 
Adjacent 
side 
Hypot-enuse 
Cosine 
ratio 
i ΔMNO ∠M = 30° 26 mm 30 mm 0.87 
ii ΔPQR ∠P = 30° 37 mm 43 mm 0.86 
iii ΔSTU ∠S = 30° 51 mm 59 mm 0.86 
Triangle Angle 
Opposite 
side 
Adjacent 
side 
Tangent 
ratio 
i ΔMNO ∠M = 45° 24 mm 24 mm 1 
ii ΔPQR ∠P = 45° 33 mm 33 mm 1 
iii ΔSTU ∠S = 45° 45 mm 45 mm 1 
25 
5 15 
30 10 20 
e 
f 
f 
d 
i 
g 
g 
h 
l 
k 
k 
j 
n 
m 
---- o 
m 
o 
b 
c 
-- a 
c 
a 
v 
u 
-- t 
u 
t 
12 
15 
30 
5 
7 
x 
-- 20 
31 
9.8 
2.7 
p 
------- 17 
t 
17.5 
H 
O 
A 
α 
H 
O 
A 
β
A n swe r s 639 
answers ➔ 
c i sin 25° = 0.42 ii cos 25° = 0.91 
iii tan 25° = 0.46 
d β = 65° 
e i sin 65° = 0.91 ii cos 65° = 0.42 
iii tan 65° = 2.17 
f They are equal. 
g They are equal. 
h The sine of an angle is equal to the cosine of its 
complement angle. 
5 a 
45° 
b O = 41 mm A = 41 mm H = 58 mm 
c i sin 45° = 0.71 ii cos 45° = 0.71 
iii tan 45° = 1.00 
d γ = 45° 
e i sin 45° = 0.71 ii cos 45° = 0.71 
iii tan 45° = 1.00 
f They are equal. g They are equal. 
h The sine of an angle is equal to the cosine of its 
complement angle. 
6 a D b B c A d D 
Maths Quest challenge (page 248) 
Exercise 7C — Finding trigonometric 
ratios using a calculator 
1 a 0.7314 b 0.9613 c 1.2349 d 0.9962 
e 28.6363 f 0.9063 g 0.5774 h 0.9903 
i 0.1392 j 0 k 0.5150 l 0.9325 
2 d i 0.5736 ii 0.8192 iii 0.7002 
Exercise 7D — Finding side lengths 
1 a 13.02 m b 7.04 m c 27.64 mm 
d 2.79 cm e 6.27 m f 14.16 m 
2 a 2.95 cm b 25.99 cm c 184.73 cm 
d 14.06 km e 8.43 km f 31.04 m 
3 a 26.96 mm b 60.09 cm c 0.84 km 
d 0.94 km e 5.59 m f 41.67 m 
g 54.73 m h 106.46 cm i 298.54 mm 
4 21.32 m 
5 285.63 m 
6 5.80 km 
7 a D b B c A 
Maths Quest challenge (page 254) 
About 62° 
Exercise 7E — Angles and the 
calculator 
1 a 0.500 b 0.707 c 0.466 d 0.839 
e 8.144 f 0.719 
2 a 0.65 b 0.59 c 0.52 d −1.50 
e 1.00 f 0.67 g 0.81 h 0.53 
i −0.80 j 0.41 k 0.99 l −0.96 
m 1.73 n −0.57 o 0.13 
3 a 50° b 24° c 53° d 71° 
e 86° f 41° 
4 a 54°29′ b 6°19′ c 0°52′ d 72°47′ 
e 44°48′ f 26°45′ 
5 a 26°33′54′′ b 64°1′25′′ c 64°46′58′′ 
d 48°5′22′′ e 36°52′12′′ f 88°41′27′′ 
6 a 2.824 b 71.014 c 20.361 d 2.828 
e 226.735 f 1.192 g 7.232 h 32.259 
i 4909.913 j 0.063 k 0.904 l 14.814 
Maths Quest challenge (page 258) 
1 a b c 
2 Any multiple of 3 (extension of part b) or power of 2 
(extension of parts a and c). 
10 Quick Questions 1 
1 sinβ = 2 0.4067 3 0.675 
4 cosθ = 5 0.54 m 6 17.11 mm 
7 45.9 cm 8 63.34 cm 9 59.14 cm 
10 2.6 m 
Exercise 7F — Finding the size of an 
angle 
1 a 67° b 47° c 69° 
2 a 54°47′ b 33°45′ c 33°33′ 
3 a 75°31′21′′ b 36°52′12′′ c 37°38′51′′ 
4 A, B, C 
5 a 41° b 30° c 48° 
6 a a = 25°47′, b = 64°13′ b d = 25°23′, e = 64°37′ 
c x = 66°12′, y = 23°48′ 
10 Quick Questions 2 
Exercise 7G — Problems involving two 
right-angled triangles 
1 a a = 15 θ = 37° β = 56° 
b x = 13.86 y = 40.52 
c x = 30° y = 56° z = 30 
d x = 56 y = 48.50 
e x = 12.77 y = 4.37 θ = 41° 
f x = 11.65 y = 24.45 θ = 39° 
g w = 11.34 x = 11.33 y = 11.34 z = 54.04 
h a = 90.46 b = 15° 
c = 93.85 if Pythagoras’ theorem used or 
c = 96.59 if sin 15° is used. 
2 z = 5.36 m, x = 4.50 m, y = 2.82 m, Area = 19.62 m2 
3 111.87 km 
Exercise 7H — Applications 
1 a 36°52′ b 53°8′ c 2.4 m 
2 a 14°29′ b 31 cm 
3 8.74 m 
4 687.7 m 
5 a 176.42 m b 152.42 m 
H O 
A 
γ 
b 
c 
-- 
-- 
y 
z 
1 3.2472 2 78° 3 74°58′ 
4 10.6 5 13.5 m 6 41° 
7 422 m 8 35°53′ 9 7.34 cm 
10 26°33′54′′ 
7A 
7H
640 A n swe r s 
answers 
6 23.88 cm 
7 a 56.83 cm b 62.50 cm 
8 65°46′ 9 6.09 m 
10 19°28′ 11 62°33′ 
12 16.04 m 
13 a 54° b 0.75 m 
14 a h = x tan 47°12′ h = (x + 38) tan 35°50′ 
b x = 76.69 m c 84.62 m 
15 a h = x tan 43°35′ h = (x + 75) tan 32°18′ 
b 148.37 m c 143.1 m 
16 a 11°32′ b 4°25′ 
17 a iii 35.36 cm ii 51.48 cm iii 51.48 cm 
iv 57.23 cm v 29°3′ vi 25°54′ 
b iii 25.74 cm ii 12.5 cm iii 25°54′ 
iv 28.61 cm 
18 a 77° b 71°56′ c 27.35 cm 
19 a 7.05 cm b 60°15′ c 8.12 cm 
20 a 28.74 cm b 40.64 cm c 66°37′ 
21 a 26.88 cm b 11.07 cm 
Maths Quest challenge (page 274) 
1 39 2 0 
Exercise 7I — Bearings 
1 a 020°T b 340°T c 215°T d 152°T 
e 034°T f 222°T 
2 a N49°E b S48°E c S87°W d N30°W 
e N86°E f S54°W 
3 a 3 km 325°T b 2.5 km 112°T c 8 km 235°T 
d 4 km 090°T, 2.5 km 035°T 
e 12 km 115°T, then 7 km 050°T 
f 300 m 310°T, then 500 m 220°T 
4 a b 
N 
c d 
e 
N 
180 km 
5 a iii 13.38 km ii 14.86 km iii 222°T 
b iii iii 51.42 km 
iii 61.28 km 
iv 310°T 
c iii 
iii 38.97 km iii 22.5 km 
iv 030°T 
6 215°T 7 A 8 1.732 km 
9 a 9.135 km b 2.305 km c 104° 10′T 
10 684.86 km 
11 B 
12 a 60°43′T b 69°27′T c 204°27′T 
History of mathematics 
1 A mountain 
2 Great Trigonometric Survey of India 
3 Leveller, zenith sector, telescope, chronometer, large 
theodolite 
Summary 
1 angle 
2 hypotenuse, opposite, adjacent 
3 sinθ = 4 cosine ratio 
5 opposite side (O) to the adjacent side (A) 
6 SOH–CAH–TOA 7 length 
8 two 9 inverse 
10 trigonometric inverses 11 angle of elevation 
12 angle of depression 13 north–south 
14 clockwise 
Chapter review 
1 a b 
c 
Adj 
θ 
2 a cosθ = b tanβ = c sinγ = 
3 B, C 
4 a 0.8090 b 0.7771 c 0.2126 
5 a 7.76 b 36.00 c 2.56 m 
----- 11 
----- 
d 19.03 e 6.79 km f 394.29 mm 
6 32.33 cm 7 7.78 m 8 1.44 m 
9 B 10 B 
11 a 9° 03 b 33° 16 c 27° 38 
12 A 
13 a 32° b 45° c 39° 
d 52° e 68° f 30° 
g 60° h 60° i 83° 
14 a 49° b c 
15 s = 41.69 t = 16.84 
16 α = 74°27′ β = 27°25′ 
40° 
100° 
N 30 km 
40 km 
240° 
135° 
N 
N 
230 km 
140 km 
120° 260° 
32° 
N 
N 
N 
0.8 km 
1.3 km 
2.1 km 
50° 
30° 40° 
S 
N 
N 
8 km 
5 km 
7 km 
30° 
70° 
20° 
N 
S 
320 km 
220 km 
42° 
130° 
N 
N 
80 km 
20 km 
A 
B 
C 
42° 
130° 
210° 
N 
N 
N 
80 km 
20 km 
45 km 
A 
B 
D 
C 
O 
---- 
H 
θ Hyp 
Opp 
Adj 
Opp Hyp 
θ 
Hyp 
Opp 
Adj 
6 
7 
-- 12 
5 
13 
′ ′ ′ 
60°4′ 36°52′12′′
A n swe r s 641 
answers ➔ 
17 74° 24 ′ 
18 0.033 km or 33 m 
19 a 10°38′ b 
6°26′ 
20 21° 
21 a 346°T b 156°T c 217°T d 048°T 
22 a S52°E b N66°W c N34°E d S38°W 
23 67.98 km 24 4.16 km 
25 
5 
8 
θ 
26 Approx 45° 
Chapter 8 Collecting and 
organising data 
Are you ready? 
1 
3 4 5 6 7 8 9 10 11 12 
2 Key: 2 | 3 = 23 
Exercise 8A — Dot plots and stem-and-leaf 
plots 
1 a 
b The scores lie between and include 6 to 20; that 
is, a range of fourteen. 
Mostly between 16 to 18 packets were sold. Sales 
of 6 and 20 packets of chips were extremely low. 
A provision of 20 packets of chips each day 
should cover the most extreme demands. 
2 a b 
c 
d 
0 1 2 3 4 5 18 19 20 21 22 
5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 6.0 
48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 
3 Check with your teacher. 
4 Key: 1 | 7 = 17 
The youngest participant is 17, the oldest is 45. The 
aerobics class was most popular among participants 
in their late teens and 20s. 
Stem Leaf 
12345 
0 9 
7 
3 3 4 8 
5 6 
2 
3 Score Tally Frequency 
1 III 3 
2 III| 5 
3 II|| || 7 
4 IIII 4 
5 II 2 
6 III 3 
4 Score Frequency 
20 5 
21 8 
22 7 
23 2 
24 4 
6 7 8 9 10111213 14151617181920 
Stem Leaf 
1234 
7 7 8 8 8 9 9 
1 1 2 3 3 4 6 8 
0 1 
1 1 5 
5 a Key: 1 | 8 = 18 b Key: 1 | 9 = 19 
Stem Leaf 
12 
8 9 9 
0 0 0 1 1 2 
Stem Leaf 
1234 
9 9 
0 4 4 5 6 7 9 
1 1 6 8 
2 3 
c Key: 33 | 6 = 336 
Stem Leaf 
33 
34 
35 
36 
37 
6 
6 6 9 
0 3 9 
2 8 
1 
d Key: 4 | 3 = 43 
Stem Leaf 
45678 
3 4 6 7 8 9 
2 5 
7 
0 7 
1 2 3 3 4 5 8 
e Key: 1 | 1 = 1.1 
Stem Leaf 
1234 
1 3 5 9 
4 7 8 9 
3 6 9 
1 2 6 
6 a Key: 1* | 8 = 18 
2 | 0 = 20 
b Key: 1* | 9 = 19 
2 | 0 = 20 
Stem Leaf 
1* 
2* 
8 9 9 
0 0 0 1 1 2 
Stem Leaf 
1* 
2* 
2* 
3* 
3* 
4* 
9 9 
0 4 4 
5 6 7 9 
1 1 
6 8 
2 3 7I 
8A
642 A n swe r s 
answers 
c Key: 33* | 6 = 336 
35 | 0 = 350 
e Key: 1 | 1 = 1.1 
1* | 5 = 1.5 
Stem Leaf 
1* 
1* 
2* 
2* 
3* 
3* 
4* 
4* 
1 3 
5 9 
4 
7 8 9 
3 
6 9 
1 2 
6 
7 a See answer at bottom of page. 
b Discuss in class. 
c Key: 10 | 0 = 10.8 
d Range = 4.2 Discuss in class. 
e Discuss in class. f Discuss in class. 
8 a Key: 6 | 3 = 63 
b See answer at bottom of page. 
c Discuss in class. d Discuss in class. 
9 Key: 0 | 1 = 1 
Mitch scored between 0 and 3 goals inclusive. 
Yani scored between 0 and 2 goals inclusive. 
10 a Mitch: 2, Yani: 3 b Mitch 
c Yani: 11 
d Yani, as he scored goals in more games. 
11 a Key: 3 | 2 = 32 
b 9A: 83%, 9B: 92% c 9A: 2 
d Discuss in class. e Discuss in class. 
f 9A: 64.3; 9B: 68.5 
g See answer at bottom of page. 
h Discuss in class. 
12 a C b D 
10 Quick Questions 1 
1 12 2 18 
3 16 4 13, 15 and 18 
5 20 6 9 
7 48 8 30 
9 28 and 39 
10 
Stem Leaf 
10 
11 
12 
13 
14 
15 
8 9 
0 2 5 8 
0 4 5 6 8 8 
2 6 6 9 9 
0 1 
0 
Stem Leaf 
6789 
3 6 7 8 9 
0 0 1 4 5 6 7 8 9 
1 2 3 6 6 7 8 9 
3 8 
d Key: 4 | 3 = 43 
4*| 6 = 46 
Stem Leaf 
33* 
34* 
34* 
35* 
35* 
36* 
36* 
37* 
6 
6 6 9 
0 3 
9281 
Stem Leaf 
4* 
4* 
5* 
5* 
6* 
6* 
7* 
7* 
8* 
8* 
3 4 
6 7 8 9 
25 
707 
1 2 3 3 4 
5 8 
Leaf Leaf 
(Mitch) 
3 2 1 1 1 1 0 0 0 0 
Stem 
0 
(Yani) 
0 0 1 1 1 1 1 2 2 2 
Leaf Leaf 
(9A) 
29 
7 4 
8 7 5 5 0 
356 
Stem 
3456789 
(9B) 
65 
0 2 8 
3 3 4 5 7 8 
1 
Key: 1 | 2 = 12 1* | 6 = 16 
Stem Leaf 
0* 
9 
1* 
1* 
6 7 9 
2* 
1 1 3 3 4 
2* 
6 6 7 8 8 8 
3* 
2 2 
3* 
5 7 9 9 9 
4* 
0 1 3 
4* 
5 6 6 7 8 
7 a 
8 b 
11 g 
10.8 11.0 
10.9 
11.2 
11.3 
11.1 
11.4 
11.5 
11.6 
11.7 
11.8 
11.9 
12.0 
12.1 
12.2 
12.3 
12.4 
12.5 
12.6 
12.7 
12.8 
12.9 
13.0 
13.1 
13.2 
13.3 
13.4 
13.5 
13.6 
13.7 
13.8 
13.9 
14.0 
14.1 
14.2 
14.3 
14.4 
14.5 
14.6 
14.7 
14.8 
14.9 
15.0 
62 64 
63 
66 
67 
65 
68 
69 
70 
71 
72 
73 
74 
75 
76 
77 
78 
79 
80 
81 
82 
83 
84 
85 
86 
87 
88 
89 
90 
91 
92 
93 
94 
95 
96 
97 
98 
32 44 
46 
48 
50 
54 
33 
43 45 
47 
49 
51 
Percentages 
52 
53 
34 
35 
36 
37 
38 
39 
40 
41 
42 
56 
57 
55 
58 
59 
60 
61 
62 
63 
64 
65 
66 
67 
68 
69 
70 
71 
72 
73 
74 
75 
76 
77 
78 
79 
80 
81 
82 
83 
84 
85 
86 
87 
88 
89 
90 
91 
92 
93 
94 
95 
96
A n swe r s 643 
answers ➔ 
Exercise 8B — Displaying ungrouped 
data 
2 
3 
4 a 
b 
c 
6 
5 
4 
14 
12 
10 
18 
16 
14 
12 
10 
b 2 c 15 d 18 
6 
7 
Number of cars 
per household 
Number of 
jelly beans per pack 
8 a Frequency column: 7, 10, 6, 4, 2, 1 
b and c 
Number of hours 
of homework 
Maths Quest challenge (page 300) 
1 
Pattern is: two dots of the same colour produce a red 
dot in the row below; two dots of different colour 
produce a black dot in the row below. The last dot in 
the row is always black. 
2 No, there must be a black dot at the end of each row. 
3 No, as pattern starts to repeat in Row 9 and no rows 
have all black dots. 
4 Yes 
Exercise 8C — Displaying grouped data 
1 Score Tally Frequency 
6 III 3 
7 III 3 
8 II 2 
9 IIII I 6 
10 III 3 
11 III 3 
12 III 3 
13 I 1 
Σf 24 
5 a x Frequency 
0 1 
1 6 
2 8 
3 5 
4 2 
5 3 
Total 25 
3 
2 
1 
6 7 8 9 1011 12 13 
Frequency 
Score 
0 
Frequency 
0 2 4 6 8 
0 1 2 3 4 5 x 
Frequency 
0 1 2 3 4 5 6 
1 2 3 4 5 6 x 
Frequency 
0 2 4 6 8 
150 151 152 153 154 155 x 
Frequency 
0 1 2 3 4 5 
50 52 54 56 58 60 x 
1 a Class 
interval 
Class 
centre Tally Frequency 
5–10 7.5 | | | | | | | | | 11 
10–15 12.5 | | | | | | | | 
| | | | | | | | 19 
15–20 17.5 | | | | 5 
20–25 22.5 | | 2 
25–30 27.5 | | | 3 
Total 40 
0 1 2 3 4 5 
10 
5 
Frequency 
Number of cars 
48 50 52 
30 
20 
10 
Frequency 
Number of jelly beans 
0 1 2 3 4 5 
10 
5 
Frequency 
Number of hours 
d 1 
Row 7 
Row 8 
Row 9 
8B 
8C
644 A n swe r s 
answers 
b 
b 
b 
c 16 
e 
Heights of Year 9 students 
157.5 
Heights of Year 9 students 
152.5 
Discuss in class. 
b 
20 
18 
16 
14 
12 
10 
2 Class 
interval 
Class 
centre Tally Frequency 
0–4 2 | | | | | 6 
5–9 7 | | | 3 
10–14 12 | | | | | | | | | | 12 
15–19 17 | | 2 
20–24 22 | | | | | | | | 9 
Total 32 
3 a Class 
interval 
Class 
centre Tally Frequency 
0–9 4.5 | | | | | 6 
10–19 14.5 | | | | | | 7 
20–29 24.5 | | | | | | | 8 
30–39 34.5 | | | | 5 
40–49 44.5 | | | | 4 
50–59 54.5 | | | | | | | | | | 12 
60–69 64.5 | | | | | | | 8 
70–79 74.5 | | | | 4 
80–89 84.5 | | 2 
Total 56 
12 
10 
Number of phone calls made per week 
4 a Class 
interval 
24.5 
44.5 
64.5 
74.5 
Class 
centre Tally Frequency 
145–150 147.5 | | 2 
150–155 152.5 | | | | 4 
155–160 157.5 | | | | | | | 8 
160–165 162.5 | | | | | | 7 
165–170 167.5 | | | | 5 
170–175 172.5 | | | 3 
175–180 177.5 | 1 
Total 30 
Hours of TV watched 
per week 
Frequency 
0 2 4 6 8 
7.5 12.517.522.527.5 x 
Frequency 
0 2 4 6 8 
4.5 
14.5 
34.5 
54.5 
Number of phone calls 
84.5 
d Class 
interval 
167.5 177.5 
Class 
centre Tally Frequency 
145–148 146.5 | 1 
148–151 149.5 | | 2 
151–154 152.5 | | 2 
154–157 155.5 | | | | 4 
157–160 158.5 | | | | 5 
160–163 161.5 | | | | 4 
163–166 164.5 | | | 3 
166–169 167.5 | | | | 5 
169–172 170.5 | | 2 
172–175 173.5 | 1 
175–178 176.5 — 0 
178–181 179.5 | 1 
Total 30 
5 a Class 
interval 
158.5 164.5 
170.5 
176.5 
Class 
centre Tally Frequency 
12–15 13.5 | | | | 4 
16–19 17.5 | | | | | | 7 
20–23 21.5 | | | | | | | | | 11 
24–27 25.5 | | | | | | | | 
| | | 13 
28–31 29.5 | | | | 4 
32–35 33.5 — 0 
36–39 37.5 | 1 
Total 40 
Frequency 
0 1 2 3 4 5 6 7 8 
147.5 
152.5 
162.5 
172.5 
Heights (cm) 
Frequency 
0 1 2 3 4 5 
146.5 
149.5 
155.5 
161.5 167.5 
Heights (cm) 
173.5 
179.5 
Frequency 
12 
10 
0 2 4 6 8 
Mathsville class sizes 
13.5 
17.5 
21.5 
25.5 
29.5 
33.5 
37.5 
Class size
A n swe r s 645 
answers ➔ 
6 a Frequency column: 3, 7, 8, 3, 3, 3, 2, 1 
b 
Forearm length of boxers 
24.5 25.5 26.5 27.5 28.5 29.5 30.5 31.5 
7 a Frequency column: 2, 5, 8, 8, 5, 2 
b, c 
100 m sprint times 
8 a Frequency column: 1, 2, 4, 6, 4, 2, 1 
Fat content of packs of bacon 
b Frequency column: 7, 10, 3 
10 
8 
Fat content of 
packs of bacon 
10 Quick Questions 2 
1 lowest score = 4, highest score = 10 
2 19 
3 9 
5 11 
6 
0 17181920 
8 15–17 
9 
10 The grouped data shows that the data is evenly 
spread while ungrouped data shows erratic changes. 
Exercise 8D — Cumulative frequency 
1 Cumulative frequency column 3, 8, 16, 28, 38, 45. 
2 
3 a 
b 53 c 37 
4 a 
4 Score Tally Frequency 
9 I 1 
10 0 
11 IIII 5 
12 II 2 
13 0 
14 III 3 
15 III 3 
16 II 2 
17 II 2 
18 I 1 
19 0 
20 I 1 
Σf = 20 
87654321 
Frequency 
Forearm length (cm) 
10.75 11.25 11.75 12.25 12.75 13.25 
8 
6 
4 
2 
Frequency 
Time (s) 
0 4 8 1216 20 24 28 
6 
4 
2 
Frequency 
Fat content (%) 
0 102030 
6 
4 
2 
Frequency 
Fat content (%) 
c The data appear 
more clustered if 
the group size is 
larger. 
7 
Class 
Class 
centre Tally Frequency 
9–11 10 IIII I 6 
12–14 13 IIII 5 
15–17 16 IIII II 7 
18–20 19 II 2 
Σf = 20 
x f cf 
16 5 5 
17 8 13 
18 6 19 
19 4 23 
20 7 30 
x f cf 
0 17 17 
1 15 32 
2 21 53 
3 10 63 
4 21 84 
5 16 100 
x f cf 
6 3 3 
7 5 8 
8 9 17 
9 4 21 
10 4 25 
321 
4 5 
9 10 11 12 13 14 15 16 
Frequency 
Score 
321 
4 5 6 7 
10 13 16 19 
Frequency 
Class centre 
8C 
8D
646 A n swe r s 
answers 
b 
c 
5 
6 a 
50 
45 
40 
35 
30 
25 
20 
b 27 
c 13 
d 70 
e 
7 a 
b 
c 
Temperatures of 90 summer days 
12 
11 
10 
Temperatures of 90 summer days 
12 
11 
10 
Frequency Score 
d 31 e 32 
8 Frequency column 5, 8, 8, 14, 5 
9 
Score for mathematics quiz 
44 
40 
36 
32 
28 
24 
20 
16 
12 
10 0 11 Check with your teacher 
x f cf 
8 5 5 
10 7 12 
12 9 21 
14 8 29 
16 11 40 
Class f cf 
1–5 8 8 
6–10 14 22 
11–15 14 36 
16–20 5 41 
21–25 9 50 
Scores of 40 
professional 
golfers 
Score Tally Frequency 
Cumulative 
Frequency 
66 IIII 4 4 
67 IIII III 8 12 
68 IIII 5 17 
69 III 3 20 
70 IIII II 7 27 
71 IIII 5 32 
72 IIII II 7 39 
73 I 1 40 
Σf = 40 
15 
10 
5 
0 1 2 3 4 5 
Cumulative frequency 
Score 
40 
36 
32 
28 
24 
20 
16 
12 
84 
66 67 68 69 70 71 72 73 
Cumulative frequency 
Score 
Score Tally Frequency 
Cumulative 
Frequency 
28 IIII IIII I 11 11 
29 IIII IIII I 11 22 
30 IIII IIII 9 31 
31 IIII 5 36 
32 IIII IIII 10 46 
33 IIII I 6 52 
34 IIII I 6 58 
35 IIII III 8 66 
36 IIII IIII II 12 78 
37 IIII IIII II 12 90 
Σf = 90 
Score Frequency 
Cumulative 
Frequency 
12 2 2 
13 3 5 
14 5 10 
15 8 18 
16 10 28 
17 6 34 
18 3 37 
19 3 40 
20 1 41 
Σf = 41 
1 2 3 4 5 6 7 8 9 
28 29 30 31 32 33 34 35 36 37 
Frequency 
Score 
1 2 3 4 5 6 7 8 9 
28 29 30 31 32 33 34 35 36 37 
4 8 
12 13 14 15 16 17 18 19 20 
Cumulative frequency 
Score
A n swe r s 647 
answers ➔ 
Chapter summary 
1 number line 2 numerical 
3 Back-to-back 4 frequency table 
5 score, tally 6 Σf 
7 histogram, polygon 8 horizontal, vertical 
9 classes 10 class centre 
11 Cumulative frequency 12 ogive 
Chapter review 
1 
Scores are distributed to the lower end. 
2 a Key: 2 | 9 = 29 
b Key: 3 | 1 = 31 3*| 7 = 37 
c Gives a better impression of the distribution 
because smaller classes give more detail. 
3 Boys Girls 
Key: 15 | 4 = 154 
4 a 
b 
b 
c 
b 
1 2 3 4 5 6 7 
0 1 2 3 4 5 
14 
12 
10 
c Key: 0 | 8 = 8 
Stem Leaf 
234 
5 5 7 7 7 7 8 8 8 9 9 9 
0 0 0 0 1 1 1 1 1 1 1 3 3 5 5 5 5 6 6 8 9 
0 0 1 2 2 3 4 4 5 6 6 6 7 8 8 9 9 
Stem Leaf 
2* 
3 
3* 
4 
4* 
5 5 7 7 7 7 8 8 8 9 9 9 
0 0 0 0 1 1 1 1 1 1 1 3 3 
5 5 5 5 6 6 8 9 
0 0 1 2 2 3 4 4 
5 6 6 6 7 8 8 9 9 
Leaf Stem Leaf 
6 
9 8 7 4 
9 7 4 0 
2 
13 
14 
15 
16 
2 8 
0 1 2 4 5 8 8 
0 
Score Tally Frequency 
8 | 1 
10 ||| 3 
12 |||| || 7 
14 |||| || 7 
16 ||| 3 
18 | 1 
Σf = 22 
0 1 2 3 4 5 
321 
4 5 6 7 
Sizes of dress sold 
8 1012 14 16 18 
Frequency 
Score 
5 a x f 
0 4 
1 5 
2 7 
3 3 
4 0 
5 1 
Σf = 20 
6 a 
Class 
4 5 
Class 
centre Tally Frequency 
0–9 4.5 || 2 
10–19 14.5 ||| 3 
20–29 24.5 |||| | 6 
30–39 34.5 |||| 5 
40–49 44.5 |||| |||| 9 
50–59 54.5 |||| |||| |||| 14 
60–69 64.5 |||| |||| 9 
70–79 74.5 || 2 
Σf = 50 
Stem Leaf 
01234567 
44.5 
64.5 
54.5 
8 9 
6 6 9 
4 4 4 7 7 8 
4 5 8 8 8 
3 4 4 6 6 7 7 9 9 
0 1 3 3 4 5 6 6 7 7 8 8 8 9 
0 1 2 2 4 4 5 5 8 
1 9 
Frequency 
0 
0 1 2 3 
Number of pets 
Number of pets 
Frequency 
0 2 4 6 8 
4.5 
14.5 
24.5 
34.5 
Weekly earnings ($) 
74.5 
8D 
8D
648 A n swe r s 
answers 
or 
Key: 0* | 8 = 8 2| 4 = 24 
b 
8 a 
Number of CDs owned 
b 11 
c 9 
9 a 
b 
50 
45 
40 
35 
30 
25 
20 
c 23 
d 17 
10 a 20 
Number of lessons to 
achieve driver's 
licence 
b Class column, 0–20, 20–40, 40–60, 60–80, 
80–100 
11 C 
12 Check with your teacher. 
Chapter 9 Congruence and 
similarity 
Are you ready? 
1 a PR b BC c d 
2 4 
3 a b c 
4 a b 
5 a b 
Stem Leaf 
0* 
1* 
1* 
2* 
2* 
3* 
3* 
4* 
4* 
5* 
5* 
6* 
6* 
7* 
7* 
8 9 
6 6 9 
4 4 4 
7 7 8 
4 
5 8 8 8 
3 4 4 
6 6 7 7 9 9 
0 1 3 3 4 
5 6 6 7 7 8 8 8 9 
0 1 2 2 4 4 
5 5 8 
19 
7 a 
Class 
Class 
Centre Tally 
Frequency 
f 
30–39 34.5 IIII IIII IIII IIII IIII 25 
40–49 44.5 IIII IIII IIII II 17 
50–59 54.5 IIII IIII IIII 14 
60–69 64.5 IIII IIII IIII IIII I 21 
70–79 74.5 IIII IIII IIII IIII III 23 
Σf = 100 
25 
20 
34.5 
54.5 
44.5 
74.5 
64.5 
Score Tally Frequency 
Cumulative 
Frequency 
0 III 3 3 
1 IIII III 8 11 
2 IIII I 6 17 
3 II 2 19 
4 I 1 20 
Σf = 20 
15 
10 
5 
Frequency 
Score (class centre) 
Score Tally Frequency 
Cumulative 
Frequency 
15 II 2 2 
16 IIII II 7 9 
17 IIII 4 13 
18 IIII II 7 20 
19 III 3 23 
20 II 2 25 
21 IIII III 8 33 
22 IIII 5 38 
23 IIII 5 43 
24 IIII II 7 50 
Σf = 50 
15 
10 
5 
15 16 17 18 19 20 21 22 23 24 
Cumulative frequency 
Score 
∠PQR ∠BAC 
P P´ 
P 
P´ 
P´ 
P 
P P' 
P 
P´ 
P P' 
P' 
P
A n swe r s 649 
answers ➔ 
Exercise 9A — Congruent figures 
1 a i and iii b i and iv c ii and iv 
2 a ΔABC and ΔPQR, SSS or SAS 
b ΔABC and ΔLMN, SSS 
c ΔLMN and ΔPQR, SAS 
d ΔABC and ΔPQR, ASA 
e ΔABC and ΔLMN, RHS 
f ΔABC and ΔDEF, ASA 
3 a x = 25° b x = 70°, y = 40° 
c x = 40°, y = 55° d x = 30°, y = 30°, z = 120° 
e x = 40°, y = 40°, z = 100° f x = 35°, y = 55° 
4 a I and II b II and IV 
c I and II, III and IV 
5 a Use SAS. b Use SAS. c Use ASA. 
d Use ASA. e Use SSS. 
6 C and D 
7 a x = 110°, y = 110°, z = 4 cm, w = 7 cm 
b x = 70° c x = 30°, y = 65° 
8 The triangles will only be similar. They may have 
different side lengths. 
9 Use SAS. 
10 Corresponding sides are not the same. 
11 Use RHS. 
Exercise 9B — Similar figures 
1 a b c 
2 a i and iii, AAA b i and ii, SSS 
c i and ii, SAS d i and iii, RHS 
e i and iii, SSS 
3 a Triangles ABC and DEC 
b Triangles PQR and ABC 
c Triangles PQR and STR 
d Triangles ABC and DEC 
e Triangles ADB and ADC 
4 ΔEDC, check with your teacher. 
5 Check with your teacher. 
6 a i 1.3 cm ii 2.6 cm b 2 
7 a -------- = BC 
------- = AC 
-------- 
b f = 9, g = 8 
8 a Yes, scale factor = 2 b No 
c Yes, scale factor = 3 d Yes, scale factor = 1.5 
e No 
9 a i = 3 -- , h = 3 1 
-- 
b j = 1.8, k = 4.53 
10 a b 
B' C' 
B' C' 
11 x = 4 12 x = 20°, y = 2 
13 x = 3, y = 4 14 8 m 
15 2.4 m 16 14.36 m 
17 100 cm and 150 cm 
18 a Yes, scale factor = 10, all sides in the equal ratio 
b No. The length increases 2 times but the width 
remains the same. 
19 8 m 
20 m = 4 cm, n = 1.5 cm 
21 8 cm 
22 a Show two sides with corresponding ratios equal 
and the included angle equal 
b Show two sides with corresponding ratios equal 
and the included angle equal 
Maths Quest challenge (page 335) 
1 
2 13.61 cm in this case. In general, the position of X can 
be found by construction as shown in the diagram. 
History of mathematics — Thales of 
Miletus 
1 He proposed the first natural cosmology and 
pioneered the scientific method. 
2 A solar eclipse. 
3 Any two of the following: 
Any circle is bisected by its diameter. 
The base angles of an isosceles triangle are equal. 
The opposite angles of intersecting straight lines are 
the same. 
The angle subtended by the diameter of a circle 
touching the circle is a right angle. 
Two triangles are congruent if they have the same 
base and base angles. 
10 Quick Questions 1 
1 1.16 m 2 5 m 
3 13 m 4 17 m 
5 1.2 m 6 a = 70°, b = 12, c = 12, d = 70° 
7 e = 19, f = 35° 8 a = 12 
9 b = 14.2 10 c = 3 , d = 7 
Exercise 9C — Area and volume of 
similar figures 
1 a 900 cm2 b 67.5 cm2 c 855 mm2 
d 102 cm2 e 5 m2 f 25 mm2 
2 a 5400 cm3 b 337.5 cm3 c 1809 mm3 
d 100 cm3 e 2.5 m3 f 1 mm3 
3 SA = 384 cm2, V = 288 cm3 
4 50 000 cm2 
5 a 250 000 cm2 b 17.4 cm2 
6 8 437 500 cm3 
7 a 1 200 000 cm2 b 187.5 cm2 
8 a 6.5 cm b 274.625 cm3 c 2 197 cm3 
d 34.3 cm3 e 28.2 cm2 
Quick Questions 2 
1 EG, ST 2 a False b True 
3 Use RHS 4 Use SAS 
5 Use SAS 6 Use equiangular test 
7 4:1 8 5:1 
9 80 cm2 10 27:64 
24 cm 
6 cm 
10 cm 1.25 m 
2 m 
AB 
AD 
DE 
AE 
1 
3 
3 
4 
3 
5 
A' 
6 
8 
10 
A' 
1 
4 
-- 
or 
A 
B 
B' 
Wall 
X 
2 
3 
-- 
-- 
1 
3 
9A 
9C
650 A n swe r s 
answers 
Exercise 9D — Transformation of 
points and figures 
1 
2 a 
b 
3 
–4 –3 –2 –1 1 2 3 4 
B CB' C' 
A D' 
B' C' 
3 a Centre of rotation: C, angle of rotation: 180° 
b Centre of rotation: B, angle of rotation: 90° 
c Centre of rotation: G, angle of rotation: 180° 
4 5 
3 
6 a b 
c 
d 
7 a P′(−2, −2), Q′(−1, 2), R′(2, −1), S′(2, 3) 
b P′(2, 2), Q′(1, −2), R′(−2, 1), S′(−2, −3) 
c P′(2, −2), Q′(−2, −1), R′(1, 2), S′(−3, 2) 
d P′(4, 2), Q′(3, −2), R′(0, 1), S′(0, −3) 
e P′(−2, −4), Q′(−1, 0), R′(2, −3), S′(2, 1) 
8 a x b y 
9 a b 
c d 
e 
B 
A' 
A' B' 
10 a 3 b 12 cm c 3.5 cm d 9 
11 a b cm2 
12 C 
13 a i (−1, 2) ii (−2, 3) iii (−1, 4) 
b x- and y-coordinates are swapped, the sign of the 
x-coordinate is changed (i.e. x′ = −y, y′ = x). 
c i (−y, x) ii (−n, m) iii (8, −2) iv (5, 3) 
v (−2, −7) 
d i (2, −4) ii (−5, 2) iii (2, −5) 
14 
–2 
–4 
15 a Side lengths and angles 
b Angles 
c Side lengths and angles 
d Side lengths and angles 
16 B 
17 P′(4, 0), Q′(4, 2), R′(5, 0) 
18 a 200 b i 6.2 m × 6 m ii 5 m × 4.8 m 
c 31.44 m2 
4 
2 
1 
–1 
R''' 
R'' 
R' 
R'''' 
R 
0 
DA' 
x 
y 
2 
2 
1 
1 3 
–1 
–2 
–2 –1 
B C 
A D 
D' 
A' 
x 
y 
2 
2 
1 
1 
–1 
–2 
–2 –1 
B 
A C 
C' 
B' 
A' 
x 
y 
2 3 
2 
1 
1 
–1 
–2 –1 
B C 
A D 
C' 
B' 
D' 
A' 
x 
y 
2 
2 
1 
1 3 
–3 –2 –1 
–1 
–2 
e 
• 
A B 
D C 
A' B' 
D' C' 
• 
A B 
C 
A' B' 
C' 
• 
A 
C 
B' 
C' 
• 
A B 
D C 
D' C' 
A • 
B 
C 
A' 
B' 
C' 
1 
2 
-- 
P 
--- 
4 
y 
2 4 6 x 
–6 
–6 –4 –2 
6 
4 
2 
• 
• 
• 
• 
• 
• 
• 
• 
K 
L 
M 
N K' 
L' 
M' 
N' 
y 
1 2 3 4 5 6 x 
3 
2 
1 
Q 
P R 
Q' 
P' R'
A n swe r s 651 
answers ➔ 
Summary 
1 Congruent 2 AAS, RHS, SSS, SAS 
3 Similar 4 
5 equal 6 equiangular, sides 
7 ≡, ||| 8 rotations, reflections 
9 translation 10 centre of rotation 
11 axis of symmetry 12 enlargement 
13 size, angles 14 image 
15 area, volume 
Chapter review 
1 a I and III, ASA or SAS b I and II, RHS 
2 a x = 8 cm b x = 70° 
c x = 30°, y = 60°, z = 90° 
3 a Use SAS. b Use ASA. 
4 Corresponding sides are not the same. 
5 a ∠P = ∠S, given angle O is common 
∠R = ∠T, third angle in a triangle, AAA. 
Other answers possible. 
b OP = OR = OS = OT (all radii) 
c If two corresponding sides are equal, that implies 
that the third side should also be equal, given all 
corresponding angles are equal. 
6 a Similar, scale factor = 1.5 
b Not similar c Similar, scale factor = 2 
7 a x = 48°, y = 4.5 cm 
b x = 86°, y = 50°, z = 12 cm 
c x = 60°, y = 15 cm, z = 12 cm 
8 a ΔABC ||| ΔDEC b ΔABC ||| ΔDEC 
c ΔABC ||| ΔPQR 
9 a Show 3 pairs of equal angles (AAA). 
b ΔABC ||| ΔEDC 
c -------- -------- AC 
BC 
dd = 5 cm, e = 4.5 cm 
= = -------- 
10 5 m 11 5 m 
12 a 10 m b 83° 
13 a 3 b 10 cm c 15 cm d 81 cm2 
14 a (4, −2) b (2, −3) c (4, −3) 
15 a b c 
y 
2 
1 
–1 
y 
2 
1 
–1 
d e f 
y 
2 
1 
–1 
Q' 
y 
2 
y 
P' Q' 
2 
R' –2 –1 1 2 
R' –2 –1 1 2 
–1 
Q' 
16 B 17 
y 
2 
S' R' 
–1 
–1 
R' S' 
Q' 
18 a (−1, 0) b (−2, 0) c (0, −1) d (−1, −1) 
19 1:6 20 1:4 21 400 cm2 
Chapter 10 Coordinate 
geometry 
Are you ready? 
1 a y = 7 b y = 1 c y = 11 
2 a y = x + 4 
b y = 3x − 2 
3 
y 
B 4 
A 
2 
E 
0 x 
–4 –2 2 4 
–2 
–4 
–6 
F 
C 
4 a Graph C b Graph B 
5 a y = x + 3 
b y = x − 2 
c y = 2x 
y 
6 
4 
2 
–4 0 x 
y 
4 
2 
–4 0 x 
–2 
y 
4 
2 
–4 0 x 
–2 
6 a 10 m b 5 cm 
Exercise 10A — Plotting linear graphs 
1 a 
b 
image ------------------------------ 
length 
object length 
AB 
ED 
EC 
DC 
–2 –1 1 2 
–2 
x 
P Q 
S R 
P' Q' 
S' R' 
–2 –1 1 2 
–2 
x 
P Q 
S R 
Q' P' 
1 
R' S' –2 –1 1 2 
–2 
x 
P Q 
S R 
P' Q' 
–2 –1 1 2 
–2 
x 
P Q 
S R 
P' 
S' 
1 
–2 
x 
P Q 
S R 
P' 
S' 
1 
–2 
x 
P Q 
S R 
S' R' 
P 
S R 
Q 
P' 
x −2 −1 0 1 2 
y 2 3 4 5 6 
x −2 −1 0 1 2 
y −8 −5 −2 1 4 
x −2 −1 0 1 2 
y 1 2 3 4 5 
D 
–2 2 4 
–2 
y = x + 3 
x −2 −1 0 1 2 
y −4 −3 −2 −1 0 
–2 2 4 
–4 
y = x – 2 
x −2 −1 0 1 2 
y −4 −2 0 2 4 
–2 2 4 
–4 
y = 2x 
x −2 −1 0 1 2 
y 1 2 3 4 5 
x 
y 
y = x + 3 
5 
21 
43 
–3–2–10 1 2 3 
–1 
–2 
y 
x −2 −1 0 1 2 
y −7 −6 −5 −4 −3 x 
21 
–2–10 1 2 3 4 5 
–1 
–2 
–3 
–4 
–5 
–6 
–7 
y = x – 5 
9D 
10A
652 A n swe r s 
answers 
c 
d 
e 
f 
g 
h 
2 a y = 0 b x = 0 
3 a 
b 
c 
d 
e 
f 
g 
h 
i 
j 
k 
l 
x −2 −1 0 1 2 
y −10 −5 0 5 10 y = 5x 
x 
y 
10 
8 
6 
42 
–3–2–1 01 2 3 
–2 
–4 
–6 
–8 
–10 
x −2 −1 0 1 2 
y 0 2 4 6 8 y = 2x + 4 
x 
y 
87 
21 
43 
5 6 
–3–2–10 1 2 3 
–1 
x −2 −1 0 1 2 
y −4 −1 2 5 8 
y = 3x + 2 
x 
y 
87 
21 
43 
5 6 
–3–2–10 1 2 3 
–1 
–2 
–3 
–4 
x −2 −1 0 1 2 
y −6 −4 −2 0 2 
x 
–3–2–10 1 2 3 
y = 2x – 2 
y 
21 
–1 
–2 
–3 
–4 
–5 
–6 
x −2 −1 0 1 2 
y −11 −7 −3 1 5 
x 
–3–2–10 1 2 3 
y = 4x – 3 
y 
4 6 
2 
–4 
–6 
–8 
–10 
–12 
x −2 −1 0 1 2 
y 8 5 2 −1 −4 
y = –3x + 2 
x 
y 
87 
21 43 5 6 
–3–2–1 0 1 2 3 
–1 
–2 
–3 
–4 
x −2 −1 0 1 2 
y 0 1 2 3 4 
y = x + 2 
x 
y 
2 3 
1 
–3–2––11 1 2 3 0 
–2 
–3 
x −2 −1 0 1 2 
y −6 −5 −4 −3 −2 
x 
–2––11 1 2 3 4 0 
y = x – 4 
y 
2 
1 
–2 
–3 
–4 
x −2 −1 0 1 2 
y −3 −2 −1 0 1 
y = x – 1 
x 
y 
2 3 
1 
–3–2––11 1 2 3 0 
–2 
–3 
x −2 −1 0 1 2 
y 3 4 5 6 7 
y = x + 5 
x 
y 
4 5 
2 3 
1 
–5–4–3–2–10 1 
x −2 −1 0 1 2 
y −6 −3 0 3 6 
y = 3x 
y 
2 3 
1 
–3–2––11 1 2 3 0 x 
–2 
–3 
x −2 −1 0 1 2 
y −14 −7 0 7 14 
y = 7x 
y 
4 6 
2 
–3–2–1 01 2 3 x 
–4 
–6 
x −2 −1 0 1 2 
y −7 −3 1 5 9 –1 
y = 4x + 1 
y 
4 6 
2 
–3–2 01 2 3 x 
–4 
–6 
x −2 −1 0 1 2 
y −7 −5 −3 −1 1 
–3–2––11 1 2 3 0 
y = 2x – 3 
y 
x 
2 3 
1 
–2 
–3 
x −2 −1 0 1 2 
y −11 −8 −5 −2 1 
x 
–3–2––11 1 2 3 0 
y = 3x – 5 
y 
1 
–2 
–3 
–4 
–5 
x −2 −1 0 1 2 
y = –2x 
y 4 2 0 −2 −4 x 
y 
2 3 
1 
–3–2––11 1 2 3 0 
–2 
–3 
x −2 −1 0 1 2 
y 14 8 2 −4 −10 x 
y = –6x + 2 
y 
2 3 
1 
–3–2––11 1 2 3 0 
–2 
–3 
x −2 −1 0 1 2 
y 14 9 4 −1 −6 
y = –5x + 4 
x 
y 
4 
2 3 
1 
–3–2––11 1 2 3 0 
–2
A n swe r s 653 
answers ➔ 
4 a b 
y = 4 
4 
–3–2––11 1 2 3 0 
c d 
5 a 
b 
c 
d 
–3–2––11 1 2 3 0 
6 a b 
–3–2––11 1 2 3 0 
c d 
7 a 
b 
c 
d 
x = –5 y 
–8 –6–4–20 2 
–2––11 1 2 0 
Exercise 10B — Gradient and 
y-intercept 
1 a Positive b Positive c Negative 
d Positive e Zero f Negative 
2 a 1 b −2 c 3 
d −1 e −3 f −1 
3 a i m = 1 ii b = −1 b i m = −2 ii b = 2 
c i m = −3ii b = 0 d i m = 3 ii b = −3 
e i m = −3ii b = 6 f i m = ii b = 4 
4 a b 3 c d−1 e – f – 
-- 1 
-- 3 
g h– -- 
i 0 
-- 1 
5 a 3 b 1 c d e3 f 2 
g −2 h 1 i 
-- 
-- 
6 78 8 C 9 B 10 A, C 11 1.7 m 
12 0.75 13 –0.23 
Maths Quest challenge (page 374) 
1 a 67 + 31 + 4 + 5 = 107, 46 + 24 + 19 + 17 = 106 
b Total of the eight numbers is an odd number. 
2 There are 6 pairs (a, b): (1, 16), (3, 13), (5, 10), (7, 7), 
(9, 4), (11, 1). 
3 When the pairs of (a, b) coordinates are plotted, the 
points lie on a straight line. 
10 Quick Questions 1 
1 (−2, 1) 2 D 
3 4negative 
5 y = 6x + 3 
6 y = −3x + 4 
7 m = 2, b = 10 
8 y = 0 
9 
10 y = 4x + 2 
x 
y 
2 3 
1 
–2 
4 
y = 1 
x 
y 
4 
2 3 
1 
–3–2––11 1 2 3 0 
–2 
1 
x 
y = –2 
y 
2 3 
1 
–2 
–3 
−2 
x 
–3–2––11 1 2 3 0 
y = –5 
y 
1 
–2 
–3 
–4 
–5 
−5 
x −2 −1 0 1 2 
y = 3 
y 3 3 3 3 3 x 
y 
2 3 
1 
–3–2––11 1 2 3 0 
–2 
–3 
x −2 −1 0 1 2 
y = 2 
y 2 2 2 2 2 x 
y 
2 3 
1 
–3–2––11 1 2 3 0 
–2 
–3 
x −2 −1 0 1 2 
y −2 −2 −2 −2 −2 x 
–3–2––11 1 2 3 0 
y = –2 
y 
2 3 
1 
–2 
–3 
x −2 −1 0 1 2 
y −4 −4 −4 −4 −4 –3–2––11 0 
1 2 3 x 
y = –4 
y 
21 
–2 
–3 
–4 
x 
y x = 1 
2 3 
1 
–2 
–3 
3 
y x = 3 
x 
2 3 
1 
–3–2––11 1 2 3 0 
–2 
–3 
−2 
−7 −7 
x 
x = –2 y 
2 3 
1 
–3–2––11 1 2 3 0 
–2 
–3 
x 
x = –7 y 
3 
21 
–8–7–6–5–4–3–2––11 1 2 0 
–2 
–3 
y 
x 2 2 2 2 2 
y −2 −1 0 1 2 x 
2 3 
1 
–3–2––11 1 2 3 0 
–2 
–3 
x = 2 
y x = 5 
x −5 5 5 5 5 
y −2 −1 0 1 2 x 
2 3 
1 
–1 1 2 3 4 5 0 
–2 
–3 
x −5 −5 −5 −5 −5 
y −2 −1 0 1 2 x 
2 3 
1 
–2 
–3 
x 0 0 0 0 0 
y −2 −1 0 1 2 x 
2 3 
1 
–2 
–3 
x = 0 
y 
1 
3 
-- 
1 
2 
-- 3 
2 
4 
2 
1 
2 
-- 7 
8 
3 
4 
2 
13 
3 
----- 
2 
3 
-- 
2 
3 
-- 
x −2 −1 0 1 2 
y 10 7 4 1 −2 
y 
10 
42 
6 8 
–4 –2 2 4 
–2 
–4 
–6 
–8 
–10 
x 
x 6 6 6 6 6 
y −2 −1 0 1 2 
y 
2 
–6 2 
6 x 
4 
4 
6 
–2–2 8 
–4 
–4 
–6 
x = 6 
10B 
10B
654 A n swe r s 
answers 
Exercise 10C — Determining the 
equation of a straight line 
1 a y = 2x − 1 b y = 3x + 4 c y = −x + 5 
d y = −4x − 2 e y = x + 2.5 f y = x − 3 
g y = – x − 1 h y = – x + 
-- 1 
-- 
-- 3 
-- 1 
-- 
2 a y = 4x b y = −x + 1 c y = − x − 2 
d y = -- x + 1 -- 1 
e y = 5 
-- x + 7 -- 3 
f y = − 3 
x − 5 
g y = – x − 3 -- 
h y = −7x − 41 
3 a y = 2x b y = x + c y = 4 
-- 
-- 1 
-- 
d y = x − 5 e y = – x − f y = – x − 
g y = – x − h y = −10x + 51 
----- 40 
-- 25 
-- 6 
----- 
----- 
4 a y = x + 1 b y = 2x − 4 c y = − x − 2 
d y = – x + 2 
-- 
5 a y = x + 1 b y = x + 4 c y = − x + 
-- 3 
-- 1 
-- 2 
-- 7 
d y = – x − 
----- 
6 a y = 2 b x = −4 
c y = x d y = −4x − 4 
-- 
7 a C b D c C, D d A, C, D 
Exercise 10D — Sketching straight line 
graphs 
1 a, d, e, f, i 
2 a b 
(1, 7) 
c d 
(1, 2) 
e f 
g h 
i 
3 D 4 B, C 
5 a i (0, 1) ii (−2, 0) b i (0, 6) ii (12, 0) 
c i (0, 5) ii ( , 0) d i (0, 50) ii (−20, 0) 
e i (0, 2) ii Does not f i Does not ii (3, 0) 
e i (0, 2) ii exist f i exist 
6 a (3, 0), (0, 3) b (−5, 0), (0, 5) 
c ( , 0), (0, 1) d (−4, 0), (0, 3) 
e (2, 0), (0, -- ) f (4, 0), (0, −2 2 
-- 
) 
g (2 -- , 0), (0, −5) h (−17 1 
-- 
, 0), (0, 7) 
i (2, 0), (0, 3) j (0.375, 0), (0, 1.5) 
10 Quick Questions 2 
1 y = 4x + 2 2 y = 3x − 10 
3 y = 1 − 2x 4 y = x + 1 
5 y = 1 − x 6 
-- 
7 y = -- x + 5 
-- 
8 y = 2x 
9 10 
Exercise 10E — Graphs of linear 
inequalities 
1 a b 
1 
2 
-- 2 
3 
3 
3 
2 
-- 1 
5 
7 
2 
3 
2 
-- 
2 
3 
3 
4 
4 
4 
1 
3 
-- 1 
3 
3 
2 
2 
3 
7 
7 
3 
3 
8 
3 
-- 17 
3 
1 
2 
-- 2 
3 
1 
3 
-- 
1 
2 
3 
3 
2 
2 
4 
5 
-- 14 
5 
7 
2 
-- 
y 
x 
2 
y 
(4, 4) 
x 
1 
y 
x 
y 
x 
–5 (1, –4) 
y 
x 
(1, –3) 
y 
x 
(1, 2) 
4 
y 
x 
(3, 1) 
3 
y 
x 
–2 (2, –3) 
y 
x 
1 
4 
1 
4 
-- 
y 
x 
3 
3 
y 
x 
5 
–5 
1 
2 
-- 
y 
x 
1 
1–2 
y 
x 
3 
–4 
2 
5 
3 
y 
2 x 
2–5 
y 
x 
–2 
4 
2–3 
1 
2 
2 
y 
x 
2 
–5 
1–2 
y 
x 
7 
–171–2 
y 
x 
3 
2 
y 
x 
1.5 
0.375 
1 
3 
-- 1 
2 
1 
2 
2 
–7 
7–6 
x 
y 
–3 
5 
x 
y 
y 
2 
0 x 
y ≤ 2 
y 
0 
x 
y ≥ 0
A n swe r s 655 
answers ➔ 
c d 
y 
e f 
y 
g h 
y 
i j 
y 
–2 0 x 
k l 
y 
m n 
y 
4 0 x 
2 a b 
y 
c d 
y 
–x  3 
–3 0 x 
e f 
g h 
i j 
y 
k l 
y 
y 
3 D 4 D 5 C 6 B 
7 a b 
y 
c d 
y 
4x + 4y ≥ 16 
e f 
y 
2 
g h 
i i 
1 
k l 
m n 
4 
o p 
0 x 
y  –1 
–1 
y 
y  6 
6 
0 x 
0 x 
y  0 
y 
0 x 
y ≥ –6 
–6 
0 x 
x ≤ 4 
y 
4 0 x 
x ≥ 0 
0 x 
x  –2 
y 
x  1 
1 
0 x 
x  0 
y 
x ≥ –1 
0 x 
–1 
0 x 
x  4 
y 
–5 
x ≤ –5 
0 x 
–x  7 
y 
–y ≤ 2 
–7 0 x 
–2 
0 x 
y 
5 
–x ≤ –5 
0 
x 
y 
4 
–y  –4 
y 
0 x 
–3 –y ≥ 3 
y 
0 x 
–2 
x + 2  0 
y 
3 
y – 3 ≥ 0 
0 x 
0 x 
8 
x – 8  0 
0 x 
4 
–x + 4 ≤ 0 
5 
y – 2  3 
0 x 
0 
–8 
–y – 6 ≥ 2 
x 
y 
–2 
4 
0 
x 
y – 2x ≥ 4 
y 
0 
x 
–1 
–1 
y + x ≤ –1 
0 
x 
4 
4 
0 
y 
x 
y – x ≥ 0 
0 
x 
y ≤ – x + 2 
y 
2 0 
x 
7 
–14 y  2x – 14 
y 
x 
y  6x –24 
0 
–24 
4 
y 
x 
21 
y ≤ –7x +21 
0 
3 
y 
x 
x + y  0 
0 
–1 
y 
x 
y ≤ x +7 
0 
7 
–7 
y 
x 
x  y –2 
0 
2 
–2 
y 
x 
y  12x –24 
0 
–24 
2 
y 
x 
3y ≥ x + 12 
0 
–12 
y 
–2y ≤ 4x +6 
x 
0 
–1.5 
–3 
y 
x 
x – y  10 
0 
–10 
10 
y 
0 
x 
y  x – 4 
–4 
4 10C 
10E
656 A n swe r s 
answers 
q r 
y 
0 
x 
2 
–4 2y  4x – 8 
s t 
0 
y 
x 
1 
2x – y  –1 
1–2 
– 
u v 
y 
6 
0 x 
y + 2x – 6 ≤ 0 
3 
w x 
y 
0 x 
–1 
y 
5 
5x + 2y – 10  0 
0 ≥ 0 x 
9x + 9y + 9 –1 
y z 
y 
0 
–4 
2 
4x – 2y ≥ 8 
0 
y 
4 
–4 
y – x – 4  0 
0 x 
1–2 
– 
y 
–2 
2y + 8x + 4 ≥ 0 
y 
0 x 
1 
–3 9x – 3y – 9  0 
y 
2 
–15x + 5y – 10  0 
2–3 
– 
8 a B b c A d D 
Exercise 10F — Parallel lines 
1 
2 b, f; c, e 
3, 4, 5 and 6 Answers will vary. 
7 a y = 3x + -- 3 
b y = − 5 
-- x − 
10 
2 
8 a 5x − y − 1 = 0 b x − 2y + 8 = 0 
c 5x + 15y − 6 = 0 
2 
0 x 
7 
----- 
7 
9 B 10 D 
11 Answers will vary. 
Exercise 10G — Perpendicular lines 
1 Answers will vary. 
2 
3 a, e; b, f; c, h; d, g 
4, 5, 6 and 7 Check with your teacher. 
8 D 9 B 
Maths Quest challenge (p. 396) 
1 Zoe plus 15 friends (16 altogether) 
2 5 different-sized squares 
Exercise 10H — Distance between two 
points 
1 AB = 5, CD = 2 10 or 6.32, EF = 3 2 
or 4.24, 
GH = 2 5 or 4.47, IJ = 5, KL = 26 
or 5.10, 
MN = 4 2 or 5.66, OP = 10 
or 3.16 
2 
a2 + 4b2 3 a2 + b2 
3, 4, 5 and 6 Answers will vary. 
7 a AB = 4.47, BC = 2.24, CD = 4.47, 
DA = 2.24 
b AC = 5, BD = 5 
c Rectangle 
8 B 9 C, D 
10 
11 a (4, 1) b (1, 1) 
Exercise 10I — Midpoint of a line 
segment 
1 
1 
-- 1 
2 
2 
-- 1 
1 
2 
-- 
2 
-- 1 
-- 1 
1 
2 
2 
3 (−3, −10) 
4 
5 D 6 C 
7 
8 
9 
-- 1 
2 
-- 
2 
-- 
2 
1 
2 
-- 
Exercise 10J — Further equations of 
straight lines 
1 y = 2x − 9 
2 3x + 2y − 8 = 0 
3 
4 
5 
6 
7 y = −x − 3 
8 4x − 6y + 23 = 0 
9 
10 
11 a A, D b C c C 
Summary 
1 linear graph 2 y = mx + b 
3 slope 4 m 
5 y-intercept 6 b 
x 
x 
a No b Yes c No d No e Yes f No 
a Yes b Yes c No d Yes e Yes f No 
a 5 b 13 c 10 d 7.07 
e 6.71 f 14.42 g 13 h 13 
i j 
a 12 b 5 c 13 d −2.2 
a (2, 5) b (3, 9 ) c (1, 6 ) d (5 , −7) 
a (−3, −3 ) b (7 , 0) c (−1, 1) 
d (0, 1 ) e (2a, b) f (a + b, a) 
a (3, 1) b 4.47 c 6.32 
a i (−1, 4) ii (1 , 1) iii 3.9 iv 7.8 
b Answers will vary. 
a i (1, −0.5) ii (1, −0.5) 
b Answers will vary. 
a i (−2, 2) ii 8.94 iii 9.55 iv 9.55 
b Isosceles triangle, height. 
a y = 3x + 2 b y = −4x + 9 
c 3x − 2y − 8 = 0 d 2x + 5y + 13 = 0 
e x + 5y + 5 = 0 f x − 3y + 17 = 0 
g x − 3y − 14 = 0 
a 2x − y + 5 = 0 b x + 2y = 0 
a 3x − 5y + 2 = 0 b 5x + 3y − 8 = 0 
a (2, 5) b 1 
c Answers will vary. d Isosceles triangle 
a y = −x + 5 b y = x + 3 c (1, 4) 
a 7x − 3y − 1 = 0 b 3x + 7y − 49 = 0 
c −7
A n swe r s 657 
answers ➔ 
7 two points 8 gradient 
9 x-intercept 10 zero 
11 x = 0 12 Parallel 
13 perpendicular 14 Pythagoras’ theorem 
15 average 
Chapter review 
1 a 
b 
c 
d 
–3–2––11 1 2 3 0 
–2 
–3–2–10 1 2 3 
–2 
–3–2–10 1 2 3 
–2 
2 a m = 1 b m = −2 c m = 3 
3 a m = 2, b = −3 b m = −1, b = 0 
c m = 4, b = −5 
4 C 
5 a 2 b 
6 a y = x + 3 
b y = −2x − 2 
c y = −x + 5 
7 a 3 b y = 2x − 1 c (4, 7) 
8 a y 
b 
(1, 4) 
c d 
1 
(3, 1) 
0 x 
9 a b 
c y 
d 
0 x 
2y + x = –5 
–21–2 
–5 
10 a b 
c d 
11 D 
12 a b 
13 a b 
c 
y 
4y + x – 2.5 = 0 
0 x 
y = x 
1 
x = 3 
0 
14 D 15 Answers will vary. 
16 C 17 Answers will vary. 
18 19 Answers will vary. 
20 A 21 (0, −18) 
22 x + 2y − 2 = 0 23 2x + 3y − 9 = 0 
24 a y = 2x + 8 b y = 2x − 10 
25 
26 
-- 5 
-- 
-- 1 
-- 1 
-- 
27 10 units 
28 y = x + 2 
29 5x − 2y + 8 = 0 as the gradient is larger 
30 (0, 5) and (8, 5). Other answers possible. 
31 x = 3. Other answers possible. 
32 Distance = units 
33 D 
x −2 −1 0 1 2 
y 2 2 2 2 2 x 
y = x – 2 
y 
2 3 
1 
–3 
x −2 −1 0 1 2 
y 3 4 5 6 7 
x 
y = x + 5 
y 
5 6 
4 
2 3 
1 
–6–5–4–3–2–10 1 
x −2 −1 0 1 2 
y −10 −6 −2 2 6 x 
y = 4x – 2 
y 
2 3 
1 
–3 
x −2 −1 0 1 2 
y −4 −1 2 5 8 x 
y = 3x + 2 
y 
2 3 
1 
–3 
5 
4 
-- 
y = –x + 5 
0 x 
y 
(1, 1.5) 
0 x 
5 y = 4x – 2.5 
–2.5 
2–3 
y = x – 1 
y 
–1 
3 
5–4 
y = 3 – x 
y 
3 
–2 
0 x 
4 
(4, –2) 
y = –6x + 25 
y 
25 
0 x 
41–6 
y 
y = 20x + 45 
0 x 
–21–4 
45 
a i − ii iii 4x + 5y − 61 = 0 
iv 5x − 4y − 25 = 0 v (9, 5) 
b Square 
a i ii (− , 1) iii (4 , 1 ) 
b Answers will vary. 
21–2 
5–8 
y 
0 1 x 
y = –3x 
–3 
1–4 
y 
0 4 x 
y 
0 x 
–2 y = –2 
y 
0 3 
x 
y 
0 3 x 
y 
x 
–3 
y 
x 
3 
–9 0 
y 
x 
3 
–2 0 
y 
x 
2 
0 4 
61 
4 
5 
4 
1 
10 
----- 1 
2 
2 
2 
34 ≈ 6 10F 
10J
658 A n swe r s 
answers 
Chapter 11 — Consumer 
arithmetic 
Are you ready? 
1 a 24 months b 156 weeks 
c 21 fortnights d 5 years 
2 a $611 b $2619.39 
c $27 493.44 d $876.92 
3 a $16.98 b $13.63 
4 12.25 hours 
5 a $12.84 b $32.25 
6 a 0.34 b 0.79 
c 0.04 d 0.672 
e 0.0825 f 0.175 
7 a $35 b $356 
c $1620 d $571.25 
8 a 14% b 65% 
c 20% 
Exercise 11A — Wages and salaries 
1 a $701.58 b $1403.15 c $3040.17 
2 a 813.46 b $1626.92 c $3525 
3 a $19 136 b $22 750 c $27 473.68 
4 a $20 358 b $21 759.40 c $26 742.56 
5 a $9.75 b $12.17 c $11.49 d $10.63 
6 a $2390 per month = $28 680 p.a. 
b $2063.58 per fortnight = $53 653.08 p.a. 
7 Paul: $40 508 
Hannah: $41 293.15 
Hannah, by $785.15 
8 $80.78 
9 $77.37 
10 $148.75 
11 Rob (Rhonda gets $342, Rob gets $349.20) 
12 $11.25 per hour 
13 Gabrielle must work 41 hours to earn more than 
Russell. 
14 a $625 b $1663.50 c $1250 d $8770 
15 B 
16 Michelle 
Exercise 11B — Working overtime 
1 a $38.43 b $114.12 c $173.25 
2 a $512.50 b $675.13 c $842.72 
3 a $12.44 b $55.98 c $528.78 
4 $542.92 
5 a $68.80 b $103.20 c $137.60 d $172.00 
6 a $24.80 b $55.80 c $49.60 d $130.20 
7 a $21.13 b $126.78 
8 Various answers. Check with your teacher. 
9 $336 
10 B 
Exercise 11C — Piecework 
1 $97.50 2 $89.50 3 $175.50 4 $213.75 
5 a $90 b 34 c $13.50 
6 a $336 b $503 c $1030 
7 a $70 b 3572 c $4.67 
8 a $52 b $9.45 
9 a $116 b $125 c $132.50 d $16.09 
10 D 
10 Quick Questions 1 
1 $1346.15 2 $29 361.80 
3 $368.60 4 $15.95 
5 $4666.67 6 38 hours 
7 $443.50 8 $538.62 
9 $446.25 10 $51.98 
Exercise 11D — Commission and 
royalties 
1 $3000 
2 a $1280 b $1115.60 
3 $1425 
4 a $200 b $620 
5 a $290 b $482.50 c $641.12 
6 a $500 b $590 c $1175 d $1568.75 
7 $7200 
8 $7450 
9 a $1920 b $2020 c $5700 
10 a $1600 b $3687.50 c $15 875 
11 a Veronica: $276 b $6000 
Francis: $216 
12 a $725 b $973 c $1078.65 
13 A 14 D 
Exercise 11E — Loadings and bonuses 
1 $529.80 2 $410.24 3 $610.85 
4 a $638.40 b $446.88 c $3000.48 
5 a $592.80 b $2786.16 
6 a $574.20 b $100.49 c $589.45 
7 a $1022 b $2401.70 
8 $744.51 
9 $45 918.37 
10 a $60 000 b $5000 c 17.9% 
11 a $73.50 b $1144.23 c $735.58 
d $90 701.81 e 6.7% 
Exercise 11F — Net earnings 
1 a $7.58 b $21.18 c $44.98 
d $158.38 e 0 
2 a $152.42 b $218.82 c $335.02 
d $601.62 e $65.00 
3 a $383.37 b $399.97 c $466.22 
4 $29 853.25 
5 $410.26 
6 a i $26.28 ii $243.72 
b i $40.73 ii $314.27 
c i $11.83 ii $173.17 
d i $53.38 ii $356.62 
e i $96.88 ii $458.12 
7 a $57.88 b 13.6% c $96.58 
d $328.42 
8 a $525.00 b $87.88 c 16.7% 
d $320.42 e 61% 
Exercise 11G — Simple interest 
1 a $1200 b $6200 
2 $1950 
3 a i $100 ii $1100 
b i $720 ii $4720 
c i $144 ii $944 
d i $263.25 ii $2963.25 
e i $5048.32 ii $20 726.32
A n swe r s 659 
answers ➔ 
4 a $3300 b $5053.75 
5 $849.32 
6 a $6162.75 b $205.43 
7 $216.00 8 2 years 6 months 
9 $1250 10 8.5% 
11 a 2 years b 2 years c $600 
d $4500 e 8% f 3.8% 
12 a $180 000 b $80 550 c $260 550 
d $4342.50 
13 a i $29.95 ii $3029.25 
b i $301.37 ii $25 301.37 
10 Quick Questions 2 
1 $2580 2 $610 
3 $8500 4 $666 666.67 
5 $480.98 6 $274.40 
7 $5250 8 $4500 
9 $6425 10 $63 293.75 
Exercise 11H — Compound interest 
1 $2317 
2 a $21 753.10 b $2753.10 
3 a $615 b $649.09 c $6128.31 
d $1525.84 e $1346.37 
4 a $5900 b Maria’s = $5921.44 
c Compounding effect 
5 $4836 6 $8840 7 $11 070 
8 a $9234 b $12 849.90 c $443.45 
d $27 800.61 e $12 667.50 f $124 254 
9 D 
10 a $20 000 b $23 466.40 
c 9.4% p.a. 
Summary 
1 salary 2 overtime 
3 commission, Royalties 4 piecework 
5 loading 6 bonus 
7 gross, net 
8 simple interest, principal, decimal, per cent, time 
period 
9 compound 10 (1 + R) 
11 initial 12 table 
Chapter review 
1 $1755.77 2 $33 225.92 
3 $129.50 4 A 
5 $460 
6 a $12.34 b $524.28 
7 a $27.50 b 80 cards 
8 $23.50 9 $570 
10 $3428.57 
11 a $938.46 b $4410.76 
12 $375 000 
13 a $490 b $77.38 
c 15.8% d $294.77 
14 a $147 b $4147 
15 $414.06 16 11.5% 
17 a $19 009.60 b $3008.60 
18 $13 760 
19 31.5 20 
21 $17.55 22 C 
Chapter 12 Summary statistics 
Are you ready? 
1 a 40 b 5 
2 a 20, 21, 22, 25, 25, 29, 34 
b 215, 276, 277, 298, 304, 325, 345, 381, 400 
c 0.3, 1.8, 2.8, 2.9, 3.1, 3.5, 3.6, 3.6, 4.6, 5.8, 5.8 
3 a 25 b 304 c 3.5 
4 a 31 b 133 
5 a 7 b 0.5 
6 a 2 b 25 c 8 
Exercise 12A — Measures of central 
tendency 
1 a 8.4 b 7.7 c 49.7 d 1.7 e 1.8 
2 a 2 b 7.8 c 24.9 d 2.3 
3 a 7 b 8 c 50 d 1.75 e 1.7 
4 a 23 b 116 c 6.28 
5 a 5 b 82 c 2.55 
6 a 5 b None c 52 d 1.5, 1.7, 1.8 
e 1.7 
7 a 1 b 7 c 30 d 2.0 
8 a 23 b 112 c 6.34 
9 a 5 b 81 c 2.4 
= 2.6 
b 2 c 2 
0 1 2 3 4 5 6 
d i Median ii Mean iii Mode 
11 a $18 000 b $29 444 c $26 000 
d i Mode ii Mean 
12 75.6 13 7 
14 a C b A c D 
b 141, 139.5, 139.6 c Mean 
1 
2 
-- 
T 
I 
PR 
= ------- 
10 a Score 
x 
Frequency 
f 
Freq. × score 
f × x 
0 1 0 
1 3 3 
2 6 12 
3 3 9 
4 3 12 
5 1 5 
6 1 6 
= 18 Σ(f × x) = 47 
15 a Score 
x 
Frequency 
f 
Freq. × score 
f × x 
137 2 274 
138 3 414 
139 5 695 
140 3 420 
141 6 846 
142 1 142 
= 20 Σ(f × x) = 2791 
Σf 
x 
Number of people 
in household 
Σf 
11A 
12A
660 A n swe r s 
answers 
16 a The median was calculated by taking the average 
of the 2 middle scores. 
b 13 
17 2 
18 a 55 250 km, 52 000 km, 52 000 km 
b Discuss in class. 
c 51 810 km; It is reduced by 3440 km. 
d 52 000 km 
e 3333 
f 50 000 km; 92% last that distance or more. 
10 Quick Questions 1 
1 23.6 2 17.5 
3 36 4 8.995 
5 9.0 6 8.0, 8.6, 9.8, 10.0 
8 3.281 25 9 4 10 3 
Exercise 12B — Grouped data — mean 
and modal class 
1 a i 63.3 ii 23.1 
b i 70–79 ii 30–40 
i 27.5 ii 30–39 
i 13.6 ii 11–15 
i 3.6 ii 3.0–3.9 and 4.0–4.9 
i 55.7 ii 60–70 
b 61.7 c 60–64, 65–59 d 60–64 
e 13; 43 % f 6.7% 
7 Score (x) Frequency (f) f × x 
1 2 2 
2 6 12 
3 9 27 
4 11 44 
5 4 20 
Σ f = 32 
2 a 
Class 
interval 
Class 
centre 
x 
Frequency 
f f × x 
0–9 4.5 10 45 
10–19 14.5 20 290 
20–29 24.5 30 735 
30–39 34.5 40 1380 
40–49 44.5 10 445 
50–59 54.5 5 272.5 
Σ f = 115 Σ( f × x) = 3167.5 
b 
Class 
interval 
Class 
centre 
x 
Frequency 
f f × x 
1–5 3 2 6 
6–10 8 9 72 
11–15 13 10 130 
16–20 18 6 108 
21–25 23 4 92 
26–30 28 1 28 
Σ f = 32 Σ( f × x) = 436 
c 
Class 
interval 
Class 
centre 
x 
Frequency 
f f × x 
0–0.9 0.45 1 0.45 
1.0–1.9 1.45 2 2.90 
2.0–2.9 2.45 4 9.80 
3.0–3.9 3.45 10 34.50 
4.0–4.9 4.45 10 44.50 
5.0–5.9 5.45 3 16.35 
Σ f = 30 Σ( f × x) = 108.5 
d 
Class 
interval 
Class 
centre 
x 
Frequency 
f f × x 
20–30 25 2 50 
30–40 35 5 175 
40–50 45 3 135 
50–60 55 12 660 
60–70 65 18 1170 
70–80 75 2 150 
Σ f = 42 Σ( f × x) = 2340 
3 a 
Class 
interval 
Class 
centre 
x 
Frequency 
f f × x 
45–49 37 2 74 
50–54 52 3 156 
55–59 57 5 285 
60–64 62 7 434 
65–69 67 7 469 
70–74 72 6 432 
Σ f = 30 Σ( f × x) = 1850 
4 a 
Class 
interval 
Class 
centre 
x 
Frequency 
f f × x 
0–9 4.5 0 0 
10–19 14.5 4 58 
20–29 24.5 6 147 
30–39 34.5 7 241.5 
40–49 44.5 8 356 
50–59 54.5 8 436 
60–69 64.5 11 709.5 
70–79 74.5 8 596 
80–89 84.5 7 591.5 
90–99 94.5 1 94.5 
Σ f = 60 Σ( f × x) = 3230 
1 
3 
--
A n swe r s 661 
answers ➔ 
b 53.8 c 16 d 60–69 
e 50–59 f 28 1 
-- 
% 
3 
g 
12 
10 
24.5 
44.5 
64.5 
54.5 
5 C 
10 Quick Questions 2 
1 4.9 
2 4 
3 4 
5 7.9625 
6 8 
7, 8 
84.5 
9 23.9 
10 21–30 
Exercise 12C — Using cumulative 
frequency to find the median 
b 8 
2 i a 
b 
c 22 
ii a 
b 
c 22 
3 a 
b 24 
30 
27 
24 
21 
18 
15 
12 
22 
20 
18 
16 
14 
12 
10 
8 
30 
25 
20 
15 
10 
5 
b Approx. 31 min c 46 d 26 
4 
Score (x) 
Frequency 
(f) f × x 
6 12 72 
7 16 112 
8 25 200 
9 17 153 
10 10 100 
Σ f = 80 Σ( f × x) = 637 
Class 
Class 
centre 
(x) 
Frequency 
(f) f × x 
1–10 5.5 4 22 
11–20 15.5 6 93 
21–30 25.5 9 229.5 
31–40 35.5 2 71 
41–50 45.5 4 182 
Σ f = 25 Σ( f × x) = 597.5 
1 a x f cf 
6 4 4 
7 3 7 
8 6 13 
9 2 15 
10 5 20 
Σ f = 20 
Frequency 
0 2 4 6 8 
4.5 
14.5 
34.5 
Percentages 
74.5 
94.5 
x 
x f cf 
20 3 3 
21 5 8 
22 9 17 
23 7 24 
24 6 30 
Σ f = 30 
x f cf 
18 2 2 
20 8 10 
22 6 16 
24 4 20 
26 2 22 
Σ f = 22 
4 a x f cf 
10 4 4 
20 8 12 
30 12 24 
40 22 46 
50 2 48 
60 2 50 
Σ f = 50 
963 
20 21 22 23 24 
Cumulative frequency 
Score 
642 
18 20 22 24 26 
Cumulative frequency 
Score 
Cumulative frequency 
0 
5 15 25 35 45 
Time taken (sec) 
Median = 25 
12B 
12C
662 A n swe r s 
answers 
i 
20 
16 
12 
4 8 
ii 28 iii 6 
i 
18 
16 
14 
12 
10 
2 4 6 8 
ii 34.5 iii 4 
b 51–60 c 61.3 
d 
50 
45 
40 
35 
30 
25 
20 
15 
10 
5 
e 59.5% f 18 
b 
30 
25 
20 
15 
10 
167 174 181 188 
c 157 d 154–160 e 9 
b 
30 
25 
20 
15 
10 
5 
c 22 d 23–27 e 21 
9 D 
Summary 
1 mean, median, mode 2 sum, number 
3 4middle 
5 frequency 6 class centre 
7 modal class 8 cumulative frequency 
9 ogive 
Chapter review 
1 a Mean = 4.9, median = 5, mode = 5 
b Mean = 60.78, median = 62, mode = 45 
c Mean = 1.54, median = 1.5, mode = 1.5 
5 a Class interval f cf 
16–20 4 4 
21–25 3 7 
26–30 5 12 
31–35 5 17 
36–40 3 20 
S f = 20 
b Class interval f cf 
8–18 3 3 
18–28 2 5 
28–38 6 11 
38–48 1 12 
48–58 2 14 
58–68 4 18 
S f = 18 
6 a 
Class 
interval 
Class 
centre 
x 
Frequency 
f 
Cum. 
frequency 
cf f × x 
41–50 45.5 10 10 455 
51–60 55.5 16 26 888 
61–70 65.5 13 39 851.5 
71–80 75.5 7 46 528.5 
81–90 85.5 4 50 342 
Σ f = 50 Σ( f × x) 
= 3065 
x 
Cumulative frequency 
0 
15 20 25 30 35 40 
Cummulative frequency 
0 
8 18 28 38 48 58 68 x 
Cummulative frequency 
0 
40 50 60 70 
80 90 
Percentage 
7 a 
Class 
interval 
Class 
centre 
x 
Frequency 
f 
Cum. 
freq. 
cf 
133–139 136 2 2 
140–146 143 3 5 
147–153 150 6 11 
154–160 157 7 18 
161–167 164 6 24 
168–174 171 2 26 
175–181 178 2 28 
182–188 185 2 30 
Σ f = 30 
8 a 
Class 
interval 
Class 
centre 
x 
Frequency 
f 
Cum. freq. 
cf 
8–12 10 3 3 
13–17 15 4 7 
18–22 20 6 13 
23–27 25 8 21 
28–32 30 5 26 
Σ f = 26 
Cumuative frequency 
0 5 
132 139 146 153 160 
Score 
Cumulative 
frequency 
0 
7 12 17 22 27 32 
Seedlings per box 
Σx 
n 
------ Σ f × x 
, ---------------- 
Σf
Mq9 nsw 5 3 answers
Mq9 nsw 5 3 answers
Mq9 nsw 5 3 answers
Mq9 nsw 5 3 answers
Mq9 nsw 5 3 answers
Mq9 nsw 5 3 answers
Mq9 nsw 5 3 answers
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Mq9 nsw 5 3 answers
Mq9 nsw 5 3 answers
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Mq9 nsw 5 3 answers

  • 1. A n swe r s 623 answers ➔ Chapter 1 Number skills Are you ready? 1 a 2 b 10 c − 14 2 a − 8 b 3 c − 10 3 a 7.8 b 6.74 c 10.043 4 a 24 b 3.29 c 56.78218 5 a 7.94 b 6.23 c 182 6 2 -- 7 37 ----- 8 a 1 ----- b 11 ----- c 1 1 ----- 1 -- 6 9 a b c 2 -- 2 d 1 e 7 f 4 -- -- -- 10 a 0.48 b 0.05 c 0.189 11 a 30 b 27 Exercise 1A — Order of operations using whole numbers 1 a 16 b 0 c 9 d 9 e 12 f 18 g 480 h 0 i 4 j 30 k 12 l 18 m 26 n 68 o 12 p 80 q 4 r 48 s 2 t 3 2 a C b D c A 3 a 12 b 10 c 8 d 6 e 0 f 44 g 2 h 78 i 92 j 4 k 0 l 3 m 14 n 0 o 340 p 0 4 3 5 $250, 100 + 2 × (100 − 25) 6 a 5 b − 7 c − 26 d − 1 e − 11 f − 13 g 10 h − 3 i 4 j 36 k − 60 l − 1 m − 3 n 24 o 30 p − 15 7 a − 2 b − 11 c − 11 d 13 e − 3 f 2 g 1 h 6 i − 9 j − 3 k − 4 8 a B b D c C 9 a 6 b − 21 c − 2 d − 5 e − 36 f − 48 g − 16 h − 2 i − 11 j −40 k 6 l −8 m 17 n −23 o −9 p 2 q 42 r 1 s 38 t 18 10 a B b A c D d B e A 11 a + b × c ÷ d − e +, − f ×, + g ×, ÷ h −, − i −, × j ×, +, × or ×, ×, − k ÷, − l +, ÷ m −, ÷ n −, × or ÷, − o −, × , + p −, −, ÷ or +, ×, − 12 95 metres 13 22°C 14 a A, B, D b C c C, D Exercise 1B — Estimation and rounding 1 a i 5.9 ii 5.89 iii 5.893 b i 67.8 ii 67.81 iii 67.806 c i 712.1 ii 712.14 iii 712.138 d i 81.1 ii 81.05 iii 81.054 e i 504.9 ii 504.90 iii 504.896 2 a 26 b 317 c 1028 d 20 3 a 3047.3 b 24.7 c 8.3 d 20.0 4 a i 600 000 ii 570 000 iii 574 000 iv 574 200 b i 400 000 ii 430 000 iii 431 000 iv 431 000 c i 30 000 ii 29 000 iii 28 600 iv 28 620 d i 1 000 000 ii 1 100 000 iii 1 070 000 iv 1 067 000 e i 500 000 ii 460 000 iii 459 000 iv 458 600 5 a 26 b 320 c 1000 d 20 6 a 0.0852 b 0.000 580 c 0.000 008 07 d 0.006 77 e 0.000 027 0 f 0.000 352 7 a 3 b 800 c 800 d 10 e 400 f 100 g 1200 h 270 i 100 j 500 k 110 l 20 m 100 000 n 696 o 60 000 8 a D b D c D d B 9 $9000 Maths Quest challenge (page 13) 1 10 km/h 2 11 of digit 0, 21 of digit 1, 20 of all of the other digits 10 Quick Questions 1 1 −18 2 6 3 4 4 15 5 −21 6 10 7 ×, ÷, +, or +, ÷, × 8 1.7466 9 0.006 060 10 90 Exercise 1C — Decimals 1 a 9.774 b 2.377 c 39.424 d 23 e 23.1 f 0.6 g −7.2 h 22.976 i 360 j 10 k 44.95 l 13.2 2 a 15.22 b 4.57 c 24.96 d 33.18 e 7.26 3 a 0.4, 0.66, 0.71 b 0.23, 2.3, 23 c 0.7, 1.04, 1.32 d 1.02, 1.1, 1.22 e 0.06, 0.5, 0.56 f 0.323, 0.35, 0.4 4 a 0.24, 0.204, 0.2004 b 0.11, 0.081, 0.062 c 0.77, 0.707, 0.7 d 0.09, 0.082, 0.0802 e 1.2304, 1.23, 1.204 f 0.39, 0.3592, 0.359 5 a C b D c B d A 6 a b c d e -------- 39 ----- 27 -- 4 ----- 3 ----- 1 -- 21 ----- 1 ----- 2 f g h 1 i 2 j k l m n o ----- -- ----------- 31 ----- 1 ----- 71 ----- 7 a 72% b 31% c 89% d 57% e 90% f 6% g 78.2% h 61.75% i 0.94% j 135% k 160.2% l 1100% m 230% n 575% o 248.5% 8 a B b B c D 9 $80.50 10 a $50 b $46.75 Maths Quest challenge (page 17) 1 36 apples 2 125 m2 3 90 s Answers 3 5 7 1 10 18 8 1 6 11 2 1 2 5 9 10 5 25 100 50 3 20 25 2 25 8 121 250 -------- 963 1000 40 16 80 1A 1C
  • 2. 624 A n swe r s answers Exercise 1D — Fractions 1 a b c d e -- 9 -- 8 -- 1 -- 4 -- 7 ----- 7 ----- 1 f g h i j k l m n o ----- -- ----- 4 -- 1 -- 1 -- -- 1 -- 1 -- 1 -- 3 2 a 4 b 4 c 12 d 6 e 2 -- 5 -- 4 -- 1 -- 3 f 4 g 2 h 5 i 9 j 7 ----- 39 ----- 35 ----- 28 ----- 24 3 a b c d e ----- 13 ----- 113 -------- 65 f g h i j ----- ----- -- 3 ----- 16 ----- 4 4 a b c d e 1 -------- 7 ----- 151 ----- 9 ----- 11 f g h 1 i j 5 k l 4 m 1 n 6 o 0 p 3 -- -- ----- ----- ----- 7 ----- 13 -- 25 ----- 5 a 45 b 21 c 30 d 54 e 13 f 52 g 105 h 14 i 176 j 90 -- 1 ----- 1 ----- 3 -- 7 ----- 1 -- 3 -- 1 -- 3 6 a , , b , , c , , -- d -- , 13 ----- , 2 -- , ----- 7 e ----- 7 , 19 ----- , 2 -- , ----- 11 f , 1 -- , 1 ----- 7 , 1 -- 5 g ----- 3 , ----- 7 , -- 1 , -- 2 h , ----- , ----- 5 i − 1 -- , − -- 1 , 1 -- j − -------- , − ----- 31 , − ----- 19 k − 1 -- , − 1 -- , ----- 1 , 1 -- l − -- , − -- 2 , -- 2 , ----- 7 , 4 -- 7 a 0.75 b 0.8 c 0.45 d 0.56 e 0.775 f 0.07 g 0.3125 h 0.0375 i 0.3 j 0.705 k 0.156 25 l 1.5 -- 3 8 a 25% b 20% c 37 % d 43 -- % e 79% -- 7 f 72% g 73 % h 55% i 83 % j 77 % k 71 % l 36 ----- % 9 a D b A c B d B e C 10 a Year 9 sold 50; Year 10 sold 10. b 40 c -- 11 Exercise 1E — Percentages 1 a 0.62 b 0.41 c 0.38 d 0.93 e 0.1 f 0.02 g 0.367 h 0.2125 i 2.5 j 3.157 k 8 l 0.006 ----- 11 -- 7 ----- 2 -------- 21 2 a b c d e -- 1 ----- 5 -- 3 -- 1 f g h i j k l m n o p ----- -- ----- 9 ----- 2 -- 4 -- 3 a 5.68 b 208 c 884 d 7.02 e 22.41 f 42 g 13.06 h 23.375 i 9.1 j 3.28 k 35.25 l 100 4 a 75% b 27% c 30% d 64% e 62.5% f 2.5% g 43.75% h 64% i 72% j 50.4% k 25.8 % l 78.5% 3 ˙ 5 a A b D c D d C e A 6 a 1300 b 1600 c 4600 d 400 e 9 f 4.5 g 250 h 204 i 900 j 120 7 a 51.75 b 8236 c 78 d 122.4 e 162.18 f 690.1 g 1430 h 3.175 i 119 8 a 38.25 b 49.4 c 72 d 1279.34 e 4571 f 96.72 g 1.068 h 368 i 80 9 a A b C c B 10 $200 000 11 $63.75 10 Quick Questions 2 1 −9 2 ----- 1 28 3 ----- 9 40.003 950 20 5 0.67 6 85% 7 31 ----- 8567.1631 50 9 41 ----- 10 $59.33 7 Exercise 1F — Index notation, square roots and higher order roots 1 a 128 b 243 c 1 000 000 d 256 e 125 f 2.89 g 39.0625 h 29.791 i 9.3025 j 0.512 16 25 ----- 8 ----- 1 ----- 81 --------------- 49 2 a b c d e 27 64 10 000 ----------- 243 ----- 1296 -------- 27 --------------- 1 32 768 59 049 f g h i j -------- 144 128 64 2401 ----------- 3125 3 a 21 b 0.3 c 9 d 1.2 e 46 f 0.23 g 26 h 11.5 i 0.24 j 2.7 4 a 21.56 b 8.12 c 48.52 d 0.99 e 4.46 f 92.87 g 1.32 h 7.54 i 4.63 j 2.37 5 a 2.4 b 1.4 c 2.9 d 3 6 a 1.614 b 9.543 c 2.721 d 3.670 7 a b c d e ----- 17 ----- 2 -- 11 -- 3 1 9 4 6 31 ----- 5 ----- 7 f g h 13 11 ----- 27 12 ----- 15 8 a 141 b 27.949 c 0.707 788 8 d 20.25 9 a D b A 10 35 600 11 778 000 000 km Exercise 1G — Further estimation and calculator use 1 a 17.664 b 8.433 c −181.284 d −3.175 e 6.794 f 3.933 g 19.458 h 0.946 i 0.397 j 34.291 k −0.448 l 0.086 m −3.846 n 4.345 o 1.131 2 a 0.055 56 b 1.994 c −57.09 d 2.188 e 1.104 f 27.98 g −0.017 30 h 82.53 i 2.421 3 a C b A Exercise 1H — Ratios 1 2 3 5 2 9 10 5 7 -- 3 8 11 12 3 3 4 -- 3 20 5 4 3 2 5 7 4 6 3 1 4 4 3 5 6 15 4 5 3 6 10 41 7 ----- 31 11 8 20 17 17 20 ----- 1 4 14 25 35 29 60 20 16 360 12 1 2 48 14 25 1 3 -- 1 4 8 2 10 3 20 20 6 5 1 2 20 3 10 20 50 5 25 11 16 ----- 1 4 12 6 15 30 3 5 5 19 ----- 5 18 17 5 8 4 79 100 40 25 7 9 10 8 3 4 3 3 10 5 1 2 4 3 4 -- 1 3 9 3 7 -- 4 11 2 5 -- 1 4 -- 97 100 50 5 10 20 1 2 4 10 8 3 19 40 ----- 1 12 11 7 9 1 6 -- a 2:3 b 1:7 c 1:3 d 2:5 e 4:3 f 4:15 g 40:31 h 36:11 i 8:25 j 100:33
  • 3. A n swe r s 625 answers ➔ 2 3 4 D 5 6 D 7 a 120 kg, 150 kg b 50 m, 550 m c 86 L, 129 L d 1875 mm, 3125 mm e 240 g, 180 g f 3.2 tonnes, 0.4 tonnes g $1000, $1500, $1500 h 50 km, 75 km, 125 km i 100 mL, 150 mL, 450 mL j 33 h, 9 h, 6 h 8 Maths 2 and Science 6 9 Brother 25, sister 35 10 a 6, 12, 18 b 40, 80, 120 c 9.60, 19.20, 28.80 11 $1350, $1650 12 67.5°, 90°, 90°, 112.5°; Trapezium 13 350 g; 500 g; 10 g 14 a 175:6428 b 37 Exercise 1I — Rates 1 a Distance and time b Distance and capacity c Money and time d Money and capacity e Capacity and time f Money and area g Area and time h Runs and overs 2 3 $487.62 4 12 5 58.8 6 1 hour 7 $45 920 8 70 9 95 hours 10 a C b A 11 a 62.5 km/h b 531.25 km/h c 17.5 km/h d 96 km/h e 13.3 m/s 12 a 63 km b 296 km c 196 km d 2550 km e 3600 m 13 a 8 h b 3 h c 6 h 30 min d 8 h 15 min e 1 h 10 min 14 a 12.5 m/s b 30 m/s c 16.67 m/s d 27.78 m/s e 41.67 m/s f 222.22 m/s 15 a 18 km/h b 66.6 km/h c 360 km/h 16 0.75% per month 17 84.5 c/L 18 11.9 L/100 km Exercise 1J — Applications 1 a −7.3°C b 10.6°C c 19° d 9°C e −14°C 2 a $190 b +$103.04 3 a $25.88 b $14.40 c $1.45 d 9 h e $786.30 f $77.78 g 3944 mL 4 209 5 a of $39 b 1045 c 8 d $24 e 320 g 6 $457.19 7 a 3740 b i 8% ii 2356 c Roald by 2 % d $19 000 8 1 608 000 000 000 000 000 9 a B b B c B d D 10 a 12.5 m b 80 mm × 72 mm 11 a 7:5:4 b Jane: $14 000, Annette $10 000, Bernadette $8000 12 a 4 hours 40 minutes b 24.9 km/h Summary 1 grouping symbols 2 point 3 significant 4 numerator 5 decimal 6 divide, percentage 7 amount 8 100 9 multiply 10 add 11 ratio 12 highest common factor 13 quantity 14 rate 15 per Chapter review 1 a 4 b 38 c 3 d 22 2 a 51 b 2 c 6 d 20 3 ×, ÷, − 4 a 5689.71 b 5700 5 a 2160 b 2156.6 6 B and C 7 a 36.615 b −2.95 8 a b ----- c ----- 11 d -------- 73 e 31 -- 23 ----- 93 -------- 2 f g h i j -------- -- 9 a b -- 10 a 71% b 240% c 93.75% d 16 % 11 D 12 a 24 b 383.5 c 373.8 13 a 0.12 b 0.346 c 0.875 d 8.25 14 a ----- b 1 ----- 3 c 2 -- 15 182.4 16 1500 17 a 57%, ----- , 0.6 b 23 -- 1 %, ----- 6 , 0.245 18 a 0.83, 82%, -- b ----- 5 , 0.416, 41% 19 a 36 b 2.05 c 1.1 20 a 267.968 75 b 875 000 21 a i 4.273 ii 4.27 b i 0.380 ii 0.380 22 a C b A c B 23 Miss Alan $5600, Mr Bradley $4200, Mrs Cato $9800, Ms Dawn $8400 24 a Karen’s b 450 km c 37.5 L 25 1.25 L for $3.60 26 a 20 m/s b 54 km/h c 4.58 c/g d 0.4%/month e 11.76 km/L 27 C 28 B 29 42 litres 30 219 030 litres 31 a 567 km b 84 km/h c $94.40 32 C and D 33 10 − 23 × −2 34 Any number between 15.395 and 15.405. 35 Any decimal greater than 0.6 and less than . 36 37 45 38 A 39 150% 40 31.5 41 20 a 6:1 b 13:15 c 4:1 d 5:1 e 1:2 f 20:3 g 1:6 h 5:3 i 5:1 j 11:5 k 43:20 l 1:200 a 3:4 b 8:7 c 2:3 d 28:25 e 9:2 f 2:7 g 10:3 h 33:16 i 23:15 j 16:65 a 1:4 b 6:5 c 100:39 d 23:2 e 1:12 f 63:125 g 400:21 h 20:1 i 1:15 j 54:5 a 18.4 points/game b $12.85/hour c 7.2 L/hour d 48c/min e 9.7 L/100 km f 85c/kg g $2.48/km h 8.5 kg/ha i 3.8 runs/over j 34 cm/year 2 3 -- 1 2 -- 7 8 -- 6 25 20 200 125 13 100 -------- 3 4 40 250 5 5 8 -- 4 5 2 3 -- 13 25 10 7 29 50 2 25 4 5 12 . 0.6 6 7 -- 1D 1J
  • 4. 626 A n swe r s answers Chapter 2 Indices Are you ready? 1 a Base is 3, power is 4 b Base is 2, power is 5 c Base is 15, power is 7 2 a 16 b 125 c 4096 3 a 3 b 11 c 17 4 a 8 b 10 c 5 5 a 2 b 5 c 9 6 a 4 b 6 c 1 7 a 5 b 10 c 6 d 4 e 2 f 5 8 a 4.7958 b 10.0995 c 6.3246 d 3.9149 e 2.2240 f 4.9324 Exercise 2A — What are indices? 1 The second option is better. 2 a 39 b 56 c 1213 Exercise 2B — Powers and bases 1 a Base = 4, power = 7 b Base = 3, power = 8 c Base = 5, power = 0 d Base = 7, power = 12 e Base = 123, power = 3 f Base = 2, power = 141 g Base = p, power = 3 h Base = e, power = 7 i Base = k, power = 10 j Base = q, power = 4 2 a 36 b 74 c e4 d 55 e 4a7 f 7y3 3 a 3 × 3 b 4 × 4 × 4 × 4 × 4 c 9 × 9 × 9 d 8 × 8 × 8 × 8 e p × p × p × p × p × p × p f b × b × b g k × k × k × k × k h a × a × a × a 4 a 16 b 2187 c 1000 d 512 e 256 f 125 g 1296 h 1 5 a B b D 6 a 6a2b3 b 4p3r4 c 15e4y2 d 30c3z e 7d2f 5g2 f 18h2i3j3 g 35ek3m2 h 40n5p2q 7 a 3 × e × e × e × e × e × e × f × f b 4 × p × p × p × p × q c 7 × t × t × p × p × p × p × p d 12 × q × q × q × r × r × t e 12 × a × a × b × b × b × b × c × c × c Exercise 2C — Multiplication using indices 1 a 3 × 3 × 3 × 3 × 3 × 3 = 36 b e × e × e × e × e × e × e = e7 c f × f × f × f × f × f × f × f = f 8 2 a 29 b 317 c 610 d 106 e 49 f g13 g h3 h a12 i p14 j q49 3 a 212 b 318 c 917 d 1011 e 126 f a11 g p21 h e22 i g26 j e36 k 4b13 l 7d16 4 a A, D b B 5 a 25p11 b 15x8 c 63y10 d 18p8 e 70t6 f 20q15 6 a 6a6e9 b 8p7h12 c 80m8 d 6g3h7 e 30p6q8 7 a 4u5 + 28u2 b 9y9d + 45y8d c 7b4c4 + 35b3c2 d 4s2t3 − 20s3t e 5h20v2 + 10h10v3 − 15h10v2 Maths Quest challenge (page 59) 1 $10 240 2 525, 526, 527 3 3 1 -- minutes 2 Exercise 2D — Division using indices 1 a b4 b w3 c q0 or 1 2 a 5 b 77 c s4 d z5 e i3 f 6 g 104 h c4 i t33 j h77 k b70 l f 900 3 a 4x2 b 6y2 c 9w7 d 3q4 e 10f 9 f 10h90 g 2j10 h 5p10 i 8g3 j 3b5 -------- 2 --------- 10n90 9m4 2 k l ------------- 7 4 a D b A, D 5 a 5p4 b 6r4 c 5a3 d 3b6 e 10r4 f 9q 6 a 2p5 b c d 8b5 3 -------- 5m10n5 ----------------- 9x8y 6 ----------- 4 p2rs2 4hk2 3 ---------------- 9a5b3c e f 3j5f 3 g h ----------- 4 3 ----------------- 20 f 6g2h4 i ----------------------- 9 Exercise 2E — Zero index 1 a 1 b 1 c 1 d 1 2 a 1 b 1 c 1 d 1 3 a 3 b 12 c 4 d 17 4 a 4r3 b 5 c 13 d -- 5 3 2 e 3 f 2b2 g ----- dh1 2 5 a 1 b 1 c 1 d 4 e 4 f 10 6 a 1 b -- c 2 d 3 2 -- 3 3a2 -------- 2 2r5 3 -- r6 -------- g ---- 2d9 f 4 e f g h 2 7 a D b A c D 8 a 1 b 2 c 2 d 2 h2 q4 e 2 f ----- g h 2 i v2 j 2x6 Maths Quest challenge (page 66) 1 33 2 5 14 15 8 4 18 11 9 17 7 6 12 16 3 10 13 2 3 -------------- 3 ----- n3 5 ----- 5 1 2 3 3 -- hours 4 When a = 1, a3 × a2 = 1, and a6 = 1. Also when a = 0, a3 × a2 = 0, and a6 = 0. But if a ≠ 1, a ≠ 0, then a3 × a2 equals a6 ÷ a. This will have a different answer to a6.
  • 5. A n swe r s 627 answers ➔ 10 Quick Questions 1 1 b 2 7 3 z5 4 27 5 262.144 6 1639 7 g8 8 p10 9 1 10 q Exercise 2F — Raising a power to another power 1 a x6 b f 80 c s100 d r144 e a10b15 f p5q15 g g15h10 h 81w36q8 i 25e10r4q8 2 a p10q6 b r15w9 c x10n18 d j18k12 e q4r20 f h24j16 g f 16g21 h t10u8 i i15j12 3 a 220 b s33 c a21 d b24 e y66 f g39 g 324x20 h 216d27 i 40 000r54 4 a B b B, D c D 5 a b6 b m4 c n3 d p8 e f 17 f g6 g y9 h y2 i c20 j g7 k k14 l p16 6 a b c d e f Exercise 2G — Negative indices 1 a -- b -- 1 c ---- d 1 2 a 5−1 b 8−1 c a−1 d q−1 3 a -- b -- 1 c 1 -- d 1 4 a b c d --- --- -- 5 a 7−2 b y−5 c z−4 d v−3 6 a b c d ------ 1 e f g h p5 ----- 21g6 7 a b c d e s f g3r6 h ------- ----- Maths Quest challenge (page 71) 1 8 2 6 3 2 Exercise 2H — Square roots and cube roots 1 a 2 b 4 c 10 d 7 e 9 f 12 2 a b b c c d d a2 3 a 2t b 3b c 10f d x e 25 f 16y4 4 a 2 b 1 c 4 d 35 e 5 f 2.1544 g 2.4662 h 2.7144 5 a e b t c b d y2 6 a 2p b 4x c 5at d 10p2 e 6y2 f 15z2t g 3ed2 h 7f 2g2 7 a B b D c A 8 a 25y b 12x c 5 d 8x 10 Quick Questions 2 1 q9 2 p2 3 5 4 a40 5 2s6t3 6 7 8q−4 8 10 9 3 10 2g2 Exercise 2I — Scientific notation (standard form) 1 a 3.15 × 102 b 4.3 × 103 c 6.7 × 1012 d 4.5 × 100 e 2.3 × 10 f 9.0 × 1016 g 6.78 × 104 h 1.22 × 10−2 i 7.89 × 10−3 j 2.3456 × 10−1 k 7.8 × 10−4 l 5.0 × 10−6 2 a 3500 b 670 c 9010 d 86 500 e 700 000 f 78 g 0.012 35 h 0.008 996 54 i 0.4323 j 0.000 07 k 0.000 432 l 0.000 008 765 3 a 1.53 × 109 b 1.035 × 105 c 4.68 × 108 d 1.05 × 1030 e 5.22 × 104 f 3.513 123 × 1016 g 4.0815 × 1010 h 2.1736 × 1013 i 2.72 × 1012 j 4.08 × 107 k 1.495 × 1042 l 1.5615 × 106 4 a 9.0 × 10 b 2.077 × 10 c 2.0 × 104 d 4.0 × 102 e 2.6 × 105 f 5.0 × 102 g 1.73 × 1013 h 2.241 04 × 102 i 1.27 × 10 j 1.9 × 104 k 2.41 × 10 l 8.0 × 1013 5 a 1.62 × 1019 b 1.3293 × 1013 c 1.606 406 × 1037 d 1.760 54 × 1022 e 8.1862 × 108 f 9.633 12 × 1018 g 2.093 75 × 102 h 2.127 65 × 102 i 2.0 × 10−10 j 4.0 × 10−2 k 1.302 857 × 1010 l 4.3 × 1013 6 a A b C 7 1.0 × 107 8 9.72 × 10–8, 4.009 × 10–6, 5.72 × 1014, 5.78 × 1014, 1.3 × 1016, 4.13 × 1072 9 a 2.544 × 106 km b 9.2856 × 108 km 10 8.849 × 103 hours Summary 1 power 2 index form 3 calculator 4 add 5 subtract 6 base 7 raising 8 variations 9 fractional, 10 multiply 11 cube 12 square root, 13 cube root, 14 Scientific notation 15 negative Chapter review 1 The second option is better. 2 a 4 b 5 c a d x 3 a 3 b 12 c 89 d 0 4 a 54 b 77 c g5 d h3j5 5 a 25 b 16 c 32 d 1000 e 81 25b8 d6 ----------- 25h20 4 j4 ------------- 8k15 27t12 ------------ 49 p18 64q44 -------------- 25y14 9z26 ------------- 256a12 2401c20 ------------------- 1 4 6 1 m p 1 x a b w 1 25 ----- 1 8 1 g4 ----- 1 k6 ---- 1 x3 ---- 1 y4 ---- 1 z6 ---- 1 q7 ----- 1 m4 ------ 3 ------ 5q m2 p 6m 1 a -- 36 ----------- 20 h3 p -------- 7 p4 15a --------- q4 b4 1 p --- 1 an ----- a 1 2 -- a 1 3 -- 2A 2I
  • 6. 628 A n swe r s answers 6 a 16 b 35 7 a b10 b m11 c k8 d f 14 e h10 f 6q17 g 35w29 h 12e5p8 8 a a3 b t4 c r7 d p3 e f 5 f y90 g m10 h g7 i x j d6 k t5 l p5 9 a 1 b 1 c 1 d 1 e 1 f a g 3 h 3 i 199 j a7 k 1 l pr m a9b4 n j8m3 10 a b8 b a24 c k70 d j200 e a15b6 f m14n24 g s3t18 h q10p300 11 C 12 a b c d 13 a x−1 b 2y−4 c z−3 d 135p−3q−3 14 a 10 b 6 c a d b e 7f 2 f 3 g 10 h x i 2d j 4f 2g 15 a 4.5 × 104 b 2.3 × 102 c 7.5 × 108 d 3.7 × 10−3 16 a 3400 b 789 000 c 345 600 000 d 0.0043 17 C 18 A 19 1.4 × 1012 20 4.167 × 108 21 9.16 × 107 km 22 1.03 × 1012, 4.601 × 1011, 4.06 × 1011, 7.34 × 10–3 Chapter 3 Geometry Are you ready? 1 GKP or PKG 2 a Reflex b Right c Obtuse d Acute e Straight f Reflex 3 a 55° b 145° 4 a x = 62° b a = 77°, b = 103° c y = 45° 5 a i Co-interior ii Corresponding iii Alternate b a = 52°, b = 128°, c = 52°, d = 128° c Line AB is not parallel to line CD. For parallel lines, alternate angles should be equal. 6 a a = 84° b b = 67° c c = 75° Exercise 3A — Angle review 1 a ∠AOB or ∠BOA b ∠MON or ∠NOM c ∠BAC or ∠CAB 2 a Reflex b Acute c Straight d Obtuse e Obtuse f Reflex g Obtuse h Right i Reflex j Revolution 3 a Complementary = 70°, supplementary = 160° b Complementary = 45°, supplementary = 135° c Complementary = 0°, supplementary = 90° d Complementary = 18°, supplementary = 108° e Complementary = 1°, supplementary = 91° f Complementary = (90 − q)°, supplementary = (180 − q)° g Complementary = (40 − n)°, supplementary = (130 − n)° h Complementary = (100 − k)°, supplementary = (190 − k)° i Complementary = (70 + p)°, supplementary = (160 + p)° j Complementary = x°, supplementary = (90 + x)° 4 a x = 50° b x = 20° c x = 160°, y = 20°, z = 160° d x = 90°, y = 72° e x = 40° f x = 160° g x = 40° h x = 330° i x = 85° j x = 30° k x = 20° l m = 45° 5 a Corresponding b Alternate c Alternate d Co-interior e Alternate f Corresponding 6 a p = 89° (alternate), q = 89° (vertically opposite p) b i = 120° (corresponding) c h = 95° (co-interior) d a = 102° (straight), b = 78° (vertically opposite), c = e = 78° (corresponding to 78°), d = f = 78° (corresponding to b) e x = 65° (co-interior), n = 115° (alternate), m = 115° (alternate), y = 65° (co-interior) f m + 40° = 70° (alternate), m = 30° g x + 60° = 80° (corresponding), x = 20° h 3x = 120° (corresponding), x = 40° i 4m = 80° (co-interior), m = 20° 7 a Parallel (corresponding angles are equal) b Not parallel (co-interior angles are not supplementary) c Not parallel (alternate angles are not equal) d Not parallel (corresponding angles are not equal) 8 Roof a as corresponding angles are equal, making the rafters parallel. 9 a 85° b 25° c 45° d 30° e 75° f 48° g 20° h a = b = c = 60° i j = 75°, k = 52.5° 10 a m = 106° b t = 110° c k = 65° d q = 122°, s = 31° e t = 105°, m = 75° f p = 64°, q = 116°, r = 64° 11 a x = 60° b x = 45° c x = 80° d x = 30° e x = 50° f x = 27° Exercise 3B — Other polygons 1 a 1080° b 900° c 1800° 2 a i 540° ii b = 120° b i 720° ii c = 130° c i 900° ii d = 30° d i 720° ii h = 80° 3 a Yes: all sides equal, all angles equal b No: not all sides equal c Yes: all sides equal, all angles equal d Yes: all sides equal, all angles equal e No: not all angles equal f Yes: all sides equal, all angles equal 4 a t = 60° b p = 108° c a = 135° d t = 150° 5 a Square b Equilateral triangle 6 120° 7 135° 8 a Dodecagon b 1800° 9 156° 10 168° 11 a 120° b 60° c 360° 12 a 108° b 72° c 360° d The sum of the exterior angles is again 360°. 13 45° 1 a -- 1 k4 ---- 2 m4 ------ 42 y5 -----
  • 7. A n swe r s 629 answers ➔ 14 24 sides 15 No, it is not possible to have a shape with sides. 16 30° Exercise 3C — Constructing triangles 1 to 3 Check with your teacher. 4 c i 5 c iii 6 Check with your teacher. 7 a b c d e f 8 4 triangles 9 2 triangles 10 10 Quick Questions 1 1 x = 24° 2 Parallelogram 3 Check with your teacher. 4 Check with your teacher. 5 C 6 C 7 A 8 True 9 36° 10 Interior 150°; exterior 30° Maths Quest challenge (page 101) 1 150° 2 36° Exercise 3D — Further sketching and constructing 1 2 3.5 cm 3.4 cm 50° 3 4 It is a right-angled triangle. 5 6 a An equilateral triangle: i Set the compasses to a desired length and, from a point at the beginning of a baseline, draw an arc. ii Then, using the same radius, and using the point of intersection of the line and the arc, draw another arc. iii Join each pair of points; that is, the starting point, the point where the line and the arc meet and the point where the two arcs meet, by straight lines. b i Draw a 4 cm line. Set the compasses at 2 cm and draw arcs from both ends of the line. ii Using a protractor, construct 120° angles at both ends of the line. iii Draw a line at this angle to intersect the arc at each end. iv Join the points of intersections of the arcs and the arms joining the angles by a straight line. 7 In a triangle, the sum of the two smaller sides needs to be more than the largest side. a The sum of the two smaller sides is less than the largest side. b The sum of the two smaller sides is equal to the largest side. c The largest side must be opposite the largest angle. 8 b Altitudes 9 Tangent 10 Decagon 11 to 16 Check with your teacher. Maths Quest challenge (page 108) 11 pieces One possible solution: 10 Quick Questions 2 1 x = 53°, y = 53° 2 y = 172° 3 y = 120° 4 m = 140° 5 u = 10°, v = 100°, w = 100°, x = 80°, y = 100°, z = 80° 6 x = 58° 7 x = 45° 8 x = 120° 9 x = 122° 10 a D b A, D c A Exercise 3E — Constructing polygons 1 Perpendicular bisectors meet outside the triangle. 2 Perpendicular bisectors meet on the hypotenuse. 3 Construct the perpendicular bisector of the base; vary the radius to get different triangles. 4 Answers will vary. 5 6 and 7 Answers will vary. 8 Find the angle bisectors of the angles formed at the centre of the circle. Join them to the circumference to create 12 vertices. Join the 12 vertices to create the dodecagon. 9 and 10 Constructions 360 23 -------- A B C D A B C D Q P S R M N L M P S R M T U D R E F M P R Q 5 cm 7 cm 8 cm C A B 6 cm 10 cm 8 cm L 7 cm 48° M N 9 cm V W X U 3.5 cm 2.5 cm 5 cm 4 cm 5.1 cm 3A 3E
  • 8. 630 A n swe r s answers 11 Create perpendicular bisectors, then angle bisectors to create 45° angles from the centre of circle, and a diameter. Exercise 3F — Geometry in architecture, design and art 1 2C 3 D 4 Figure a, tall adult; figure b, short child 5 Construction 6 Approximately 1.6 to 1 7 a b − a b -- c ----------- a d b2 − ab − a2 = 0 e = ------------------- (disregard negative value for b) f ---------------- , approximately 1.618 8 a Long side = 6.472 b Short side = 2.472 c Long side = 18.171 d Short side = 309.326 9 a Regular triangle, square b 3, 3, 3, 4, 4 and 3, 3, 3, 3, 3, 3; irregular 10 Summary 1 smaller than 2 obtuse 3 180º 4 reflex 5 transversal 6 adjacent 7 360° 8 number of sides 9 divide 10 regular 11 pair of compasses 12 protractor 13 exterior 14 bisector 15 perpendicular 16 sketching 17 circumcentre 18 vertex 19 alternate 20 Tessellations Chapter review 1 a 60° b 50° c a = 120°, z = 60° d a = 60°, c = 60° e f = 80°, d = 80° f g = 70°, h = 70°, j = 110° g 75° h 40° i 10° 2 a x = 83°, y = 97° b x = 70° c x = 60° d x = 50° e x = 20° f m = 35° g x = 107° h x = 75°, y = 25° i x = 280° 3 a 540° b 1080° 4 a x = 110° b m = 50° c m = 45° 5 Check with your teacher. 6 Make a 60° angle, bisect it, then bisect one of the smaller (30°) angles. 7 Make a straight angle, then a 60° angle, then bisect the 60° angle. Its supplement is 150°. 8 a b Angle subtended by each side at centre = 36° 9 There are 10 differently shaped triangles. 10 C 11 p = 108° 12 B 13 B Chapter 4 Algebraic expressions and relationships Are you ready? 1 a 6 + 4 b 2 × 5 c 7 − 3 2 a D b E c A d B e C 3 a 3a, −4a, a b 5x, x, x c 7qp, 7pq d ac, 2ac 4 a 13y b 3n + 4m c 7x + 4 d 9k + 2p 5 a 12x b 21ab c −5kp d 6m2n 6 a 3x b 15 c 4 d −7xy 7 a 2x + 6 b 3y − 3k c −5m − 10 d −7a + 28 8 a 18 b −15 c −3 d 9 e 25 f 80 g 60 h 2 Exercise 4A — Generalised arithmetic 1 a 3 b 7 c −2 d −8 e 1 f −1 g h i − j − 2 a 6 b 7 c 3 d −2 e 3 f −2 g −7 h −11 i − j k 1 l 0 3 a i 3 ii 5 iii 8 iv 5x2 b i 3 ii −9 iii −6 iv −9m2 c i 4 ii 5 iii 5 iv −7x2 d i 4 ii 9 iii 4 iv −9b2 e i 5 ii 11 iii −4 iv −7q f i 5 ii −9 iii 5 iv −9p g i 4 ii 4 iii −2 iv −3ac h i 5 ii 5 iii 9 iv −3u i i 5 ii −1 iii 8 iv −m j i 5 ii 7 iii 14 iv −3cd2 b a b – a b a + 5a 2 1 + 5 2 Five different triangles Three different triangles 1 2 -- -- 1 -- 1 -- 1 1 3 2 4 -- 9 2 3 -- 1 -- 4
  • 9. A n swe r s 631 answers ➔ 4 a p + 2 b q − 7 c 3p + 2 d 9q − 7 e 10 − 4p f 5 − 2p g p + q h p − q i 3p + q j p − 2q k pq l 4pq m + 3q 2p 3q n 2q − 3p o ------ p ------ 5 a B b D c A d B 6 a 11 b x + 5 c y + 5 7 a 3.5 km b (x + 2) km 8 a 4 b 2.5 + t c 2.5 − y 9 a 10n, where n = number of shirts b N + 30, where N = Nick’s dollars c 7g − 4, where g = goals scored 10 a i 94 ii 6x + y b i 66 ii 6p + q c i 28 ii 6x + y − 6p − q 11 xy dollars 12 cents worth of chips 13 a b ------ 30 – d 4 14 a (30 − d) cm b cm c cm ----------------------- x 4 -- x -- x 15 a b c − -- -------------- 24 – c 16 a hours b (c + -------------- ) hours 17 a 1 b 8.30 pm and 9.30 pm c 5 d 24 e 7.30 pm and 8.00 pm f None of Marty’s friends left and then returned, and also nobody arrived who hadn’t been invited. Exercise 4B — Simplifying algebraic expressions 1 a 9ab, −ab b 4x c −3za, −az d 2x2, −x2 e −2x2y f −x2y5, −3x2y5 g p3x2w5, −5x2p3w5 h 4y5z4x2, −2x2z4y5 2 a 7x b 11y c 19m d 11q e 8r f 5x g 8a h 8y i 13x j 16p k 9q2 l 3x2 m 8x2 − 3y n 2m2 + 2n o 7x2 + x p 9h2 + h + 9 q −2g2 + g − 12 r −5m2 + m + 15 s 12a2 + b + 4b2 t 3m + 7n2 u 12xy + 2y2 v 2ab + 5a2b w 16x2y − 3xy x m2n + 11n y −3xy + 9x2 z 8m2n + 5mn2 3 a B b D c A d D 4 a 6mn b 20xy c 8pq d −10xy e −12xy f 15mn g 10a2 h 20y2 i 5p2 j 7m2 k 6mnp l −6ab2 m 10m2n n −18a2b o 30x3y2 p −12p2q3 q −56c3d r 30a4b7 5 a 3x b 3m c 2y d 4m e 4m f 2x g −7x h −4m i j -- ----- 1 ------- 1 k l m n o 2yz ----- 7yz p q r − 6 a 40x2y2 b 56ax2y2 c 12x3y2 d e− ------ f 2 g 40a3b2 h −8a3b3 i 16a4 Maths Quest challenge (page 141) 1 21x + 23y, 34x + 37y, 55x + 60y 2 Hint: Let n represent the number of the month and d represent the day of the month. Form an algebraic expression from the instructions given. Show how this becomes 100n + d. 10 Quick Questions 1 1 12 2 550 − y 3 4 + t 4 (100 − q) cm 5 B 6 + 7 5x2 + 7x 8 12x2 + 2y 9 6x3 10 4r2 Exercise 4C — Expanding to remove grouping symbols 1 a 3x + 6 b 4x + 12 c 5m + 20 d 2p + 10 e 4x + 4 f 7x − 7 g −4y − 24 h −5a − 5 i −3p + 6 j −x + 1 k −x − 3 l −x + 2 m 6b − 12 n 24m − 16 o −30m + 24 p −27p + 15 2 a x2 + 2x b y2 + 3y c a2 + 5a d c2 + 4c e 4x + x2 f 5y + y2 g 7m − m2 h 8q − q2 i 2xy + 4x j 5pq + 20p k −3xy − 12y l −10pq − 90p m −3b + ab n −35m + 7mn o −30a + 18a2 p −28x + 16x2 3 a 2p − 2 b 5x − 17 c −7p − 17 d −12p + 3 e 6x2 − 20x f 2m2 + 7m g 3px + 6x − 5 h 4y2 − 4y + 7 i −4p2 + 13p j 4x − 13y k 2m2 − 8m − 4 l −3p2 + 10pq − 1 m −30a + 10ab n 7cd − 12c2 − 5c o −2p − 17 p 3 − 3m Exercise 4D — Simplifying expressions with grouping symbols 1 a 8x + y b 10p + 8q c 18a + 29b d 19c + 22d e 2m − 11n f 6x − 11y g 9x + 5y h −14p − 8q i −4a + 3b j 4x − y k 5p − 10q l −8c + 9d m 13x − 19y n −7p + 11q o −5a + 3b p 8c + d 2 a 2ab + 2a − 3b b 2xy + 4x − 2y c 2cd + 3c d 2pq − 2p e 5cd − 11c f 5ab − 21a − 3b g 5m h 6cd − 36c i 6m2 + 6m − 10 j 9cd − 8c k −15a2 + 2b2 − 9ab l −8c2 + 3d2 + 22cd m 12m2 − 20m − 4 n 2p2 + 7p − 6 o −7x2 + 41x − 6 p −10y2 − 6y − 12 3 a B b A c D p 2q p x y -- x n -- x 2n -------------- 3(30 – d) 4 -- x 6 4 6 24 – c 7 7 m 2 ---- x 3 4m 9 ------- 4x 3 5m ------ 2a 35ab 2 ------------ xy 4 -------- 11 x2 2y ----- 5a 4b x 3 -- x -- 5 3F 4D
  • 10. 632 A n swe r s answers Exercise 4E — Algebraic fractions 1 a b -- c − m d e -- 9m ---- x --- 17q --------- p --------- x f g h − i j --------- 25 ------- 7 -------- 11 ------ 11 2 a – b c – d e f ------- -- -------- ------ b 3 a 3ab b c d e 3 ------- 1 ----- n f g h i 14 j -- 4m ------- 2q ------ 1 k l m n o -- -- 4 a 3ab b 2x c d ------ e 3 ------ 7b5 ----- 3a -- 3 f g 4 h i j -- x3 ------ 1 ------ 3q k l m n o 10 Quick Questions 2 1 5m + 4n 2 6 − x 3 (60 − p) cm 4 4y2 − 2y + 2 5 8mn 6 7 86yz -------- ----- 9 10 Exercise 4F — Substitution and formulas 1 a 7 b −40 c 7 2 a 32 volts b 250 volts c 240 volts d 245 volts 3 a 15 b 10 c 18 d 45 e 30 f 10.72 g 21 h 22.4 i 50 j 171 k 4 l −30 m 32.75 n 38.33 o 34.54 4 a i 12 cm2 ii 5 cm2 iii 1.5 cm2 b i 15 ii 6 iii 0 c i 5 ii 13 iii 10 d i 63 cm3 ii 580 cm3 iii 8.28 cm3 e i 10 ii 15 iii 20 f i 19.44 ii 32.4 iii 10 g i 461.58 ii 69 360.09 iii 78.11 h i 1670.48 ii 150.72 iii 226.33 History of mathematics 1 Heron invented machines and toys such as fountains, syphons and steam engines which were operated by water, steam or compressed air. 2 It works out the area of a triangle using the side lengths of the triangle. 3 He was a mathematician and astronomer in India. 4 It works out the maximum area of a quadrilateral using the side lengths. 5 Heron’s formula is the same as Brahmagupta’s with one of the side lengths set to 0. Summary 1 term 2 coefficient 3 pronumeral 4 equation 5 like 6 10x − y 7 worded question 8 like terms 9 inside 10 collect like terms 11 10x + 6 12 lowest common denominator 13 denominators, cancelling 14 multiplication, reciprocal 15 substitute Chapter review 1 a i 4 ii −8 iii −5 iv −8xy2 b i y + 8 ii x − y iii x + y iv 7xy v 5y − 2x 2 a xy dollars b i (24 − k) m ii m 3 a 17p b 10m2 c y2 + 2y d 10ab + 3b2 e −3s2t f 4x + 9xy g 16c2d − 2cd h 5x2y − 6 i n2 − 4p2q + 6 j 15ab − 3a2b2 4 a 12ab b −5y2 c 2ab2 d 6p2q e 8x2y2 ------- 9 -- 1 ------ 1 f 5a g h i j 5 a 5x + 15 b −y − 5 c −3x + 2x2 d −8m2 − 4m -- 6 a 3x + 3 b −10m − 1 c 4m2 − 9m − 5 d 4p − 6 7 a 9a + 8b b −5x − 18y c 11m − mn d 4x2 − 10x + 3 -- 31 ----- x 8 a b c d ---------- e 2 -- 2 -- 2 f g h i j 2 -- 5 -- x k l m n -- ------ 9 a 23 b 134 10 a 307.72 cm3 b 5377.26 cm3 Maths Quest challenge (page 160) 1 Let D = dark coloured counter, L = light coloured counter, S = empty space so starting position is DDSLL. Solution is: DDLSL, DSLDL, SDLDL, LDSDL, LDLDS, LDLSD, LSLDD, LLSDD 2 Possible solution is DDDLSLL, DDSLDLL, DSDLDLL, DLDSDLL, DLDLDSL, DLDLDLS, DLDLSLD, DLSLDLD, SLDLDLD, LSDLDLD, LLDSDLD, LLDLDSD, LLDLSDD, LLSLDDD, LLLSDDD. 7x 12 ----- y 6 8 4 14 2t 15 ----- 13a 10 6 15 6 1 2 p 10x 4m 20b 18c 10 + 12y 15y2 --------------------- 2x y ----- q 4 p 5a2 -------- 1 3 -- m 12 6m 9 8 y -- 5 3 21 45 4 1 3y ----- p 4q 1 3 10 2 4 3m3 5 --------- 8b 3c 5 2 5y -- x 8 7x 10 ----- 23 20b --------- 7z ----- 12 2 3 -- 24 – k 3 -------------- x 3 7m 2b 5 7x 10 ----- x 12 8 24m 1 4 -- 1 4 5 3 1 6 -- 3 7 6 2b
  • 11. A n swe r s 633 answers ➔ Chapter 5 Linear equations and inequalities Are you ready? 1 a x + 2 = 9 b 8x = 40 c x − 11 = 3 d = 2 2 a x = 6 b y = 13 c k = 15 d x = −51 3 a Yes b No c No d Yes 4 a x = 3 b a = 6 c m = 0 d y = −1 5 a 6x − 12 b −2y − 2 c 8a + 12 d −10p + 35 6 a b c d 7 a No b No c Yes d Yes 8 a b = 4 b l = 13 Exercise 5A — What is a linear equation? 1 a, b, d, e, f, h, k, l 2 a x + 3 = 5 b x − 9 = 7 c 7x = 24 d = 11 e = −9 f 5x = −7 g 14 − x = −3 h 3x + 5 = 8 i 2x − 12 = 15 j = 5 3 a B b D c B d B Maths Quest challenge (page 165) 1 332 pages 2 6 years ago Exercise 5B — Solving simple equations 1 a x = 210 b x = 52 c x = 230 d x = 23 e x = 142 f x = 96 g x = 37 h x = 20 i x = 50 j x = 138 k x = 442 l x = 243 m y = −15 n y = 1.8 o y = 12.8 p y = 2 q y = 24 r y = − s y = 21.5 t y = 172.5 u y = −8.32 2 a x = 5 b x = −2 c x = 0.2 d x = 1 e x = 1 f x = 2 g x = 5 h x = −1 i x = 24.5 j x = 1.2 k x = 22.25 l x = 3 a x = 1 b x = −2 c x = 3 d x = −6 e x = −1 f x = g x = 1 h x = –2.32 i x = 3 j x = − k x = 1 l x = 3 -- 1 4 a y = −1 b y = 1 c y = 0 ----- d y = 5 e y = −8.6 f y = −0.9 g y = 8.9 h y = 19 i y = −26 j y = −1 k y = −1 l y = −1 5 a x = −15 b x = 16 c x = −66 d x = 12 e x = −3 f x = 4 g x = 9 h x = −1 i x = 9 j x = −2 k x = −7 l x = -- 1 -- -- 2 -- 6 a z = 16 b z = 31 c z = −4 d z = 6 e z = −9 f z = −6 g z = −1.9 h z = 6.88 i z = 140 j z = 0.6 k z = −35.4 l z = 8 7 a x = 1 b x = 13 c x = −2 d x = −8 e x = −4 f x = 30 g x = −6 h x = − i x = 10.35 j x = −0.046 k x = 22 l x = −5 8 a x = 4 b x = c x = −1 -- d x = −6 -- e x = ----- 4 f x = 8 g x = −6 h x = 7.5 i x = 5.1 j x = −6 k x = −5 l x = −61 -- 9 a C b D c C 10 a a = −1 b b = 10 c c = 12.1 d d = 4 e e = 5 f f = 12 g g = 15.97 h h = 31 i i = j j = k k = −8 l l = 10.3 Maths Quest challenge (page 173) 1 5 days 2 4 3 30° 10 Quick Questions 1 1 x = −3 2 x = 5 3 x = −12 4 x = 2.7 5 x = 2 or 2.8 6 x = −42 7 x = 5 or 5.25 8 x = 1.357 (to 3 dp) 9 x = 7 10 x = 0 Exercise 5C — Solving equations with pronumerals on both sides 1 a y = −1 b y = 1 c y = −3 d y = −5 e y = −45 f y = g y = −2 h y = 20 i y = 1 j y = −1 k y = 4 l y = −2 2 a C b A 3 a x = 1 b x = −2 c x = 3 d x = 4 e x = 9 f x = 3 g x = −2 h x = 4 i x = −4 j x = k x = 0 l x = − x 6 -- –5 –4 –3 –2 –1 0 1 2 3 4 5 x x 2 x 5 –4 –3 –2 –1 0 1 2 3 4 5 6 x x 0 –5 –4 –3 –2 –1 0 1 2 3 4 5 x x –1 –5 –4 –3 –2 –1 0 1 2 3 4 5 x x 5 -- x -- 2 3x 2 ----- -- 1 1 3 ----- 18 -- 2 1 3 -- 3 383 600 -------- 1 2 -- 2 3 -- 5 6 -- 1 4 13 1 5 3 1 4 3 1 2 -- 7 10 ----- 3 7 -- 1 7 2 3 45 13 15 ----- 3 7 13 226 -------- 1 6 -- 1 6 -- 4 5 -- 1 4 -- 8 27 ----- 1 5 -- 1 2 -- 4E -- 3 4 5C
  • 12. 634 A n swe r s answers 4 a x = −6 b x = 7 c x = 2 d x = −2 e x = 13 f x = −7 g x = -- h x = − ----- 2 i x = 1 5 a D b C Maths Quest challenge (page 175) 1 kg or approx. 667 g 2 4 Exercise 5D — Solving linear equations with grouping symbols 1 a x = 6 b x = –3 c x = 0 d x = 56 e x = 1 f x = 0 g x = −1 h x = −2 i x = 6 j x = 0 k x = −0.8 l x = 6 2 a b = 1 -- b m = 4 -- 1 c a = −1 1 -- d m = −1 -- e p = -- 3 f m = 2 -- 2 g a = −1 h p = 1 -- i a = 3 1 -- j m = −2 -- k a = − -- 1 l m = − 1 -- 3 a x = 16 b x = 2 c a = 5 d b = 7 e y = 7 f x = −3 g m = 4 h y = 1 i a = 5 j p = −2 k m = 3 l p = 1 4 a y = −7.5 b y = −4.667 c y = −26.25 d y = 8.571 e y = −2.9 f y = 3.243 g y = 3.667 h y = 2.75 i y = 1.976 j y = −2 k y = −3.167 l y = 1.98 5 a D b C 6 a x = 5 b x = −3 c x = −8 d x = −7 -- e x = 4 f x = ----- 10 g x = −18 h x = 3 -- i x = 2 -- j x = −1 k x = 0 l x = −15 Maths Quest challenge (page 177) 1 27 2 6 Exercise 5E — Solving problems with linear equations 1 0 2 60 years 3 a 11.88 km b He will have to walk 1.12 km (1 km and 120 m). 4 23 passengers 5 a 0.06x b (1 − x) c 0.03(1 − x) d 0.06x + 0.03(1 − x) = 0.05 e 0.667 or 66.7% 6 947 7 a Post quick distributor, cost = $700 b 333 flyers, cost = $366.67 8 24 km 9 21 ≈ 21.9 km 10 6, 7, 8, 9, or 10 books 11 a 10 + 1.5(x − 3) + 1(x − 6) b Check with your teacher. c Mississippi.com is $4.50 more expensive. d 14 books 10 Quick Questions 2 1 x = −92 2 x = 3 x = −3 4 x = 28 5 x = −4 6 x = −16 7 x = 3 8 0.156 9 46 10 118 Exercise 5F — Solving more complex equations 1 a x = b x = 3 c x = d x = −7 e x = −2 f x = g x = −5 h x = 5 i x = −2 j x = −2 k x = 2 l x = −6 2 a x = b x = 15 c x = −6 d x = − e x = −1 f x = −192 g x = h x = 12 i x = 3 j x = 3 k x = 52 l x = 1 3 a x = b x = 1 c x = 4 d x = −3 e x = 5 f x = −1 g x = 1 h x = −4 i x = 1.5 j x = −4 k x = 3 l x = 1 4 a B b A Exercise 5G — Solving linear inequalities 1 a x 2 b a −1 c y ≥ 7 d m ≥ 4 e p 1 f x 7 g m ≤ 9 h a ≤ 7 i x 3 j m ≥ 2 k q ≥ −4 l a −8 2 a m 3 b p ≤ 2 c a 4 d x ≥ 5 e p −5 f x ≤ −7 g m ≥ −0.5 h b −0.5 i m 18 j x 8 k a ≤ –14 l m ≥ 25 3 a m 4.5 b x ≥ 3 c p 4 d n ≤ 2 e b 5 f y 2 g m ≤ −1 h a ≥ −5 i b −4 j c ≤ −1 k p −2 l a ≥ −7 4 a m 3 b a ≥ 2 c a −1 d a ≤ −3 e x 6 f x ≤ 2 g b 4 h a 5 i m 2 j m ≤ 3 k b ≤ −1 l m ≥ 1 5 a x ≤ 7 b x ≥ −18 c x −10 d x 10 e x ≥ 5 f x −1 6 a m −2 b p ≥ −3 c a ≤ 5 d p ≥ −5 e y ≤ −3 f x 7 g p 0 h a ≥ i x –3 j a ≤ −11 k b ≤ 3 l x −3 m k 8 n x −18 o a ≤ 40 7 B 8 a x −1 b m ≤ −3 c x 17 d a e m ≥ 1 f m ≥ −12 1 6 17 2 3 -- 1 6 2 2 1 3 5 3 1 2 -- 1 2 3 1 2 6 4 1 9 -- 1 3 -- 1 2 11 2 3 3 3 7 -- 123 137 -------- 5 11 ----- 5 9 -- -- 29 ----- 5 20 31 8 ----- 36 ----- 3 ----- 10 8 11 43 -- 4 11 12 ----- 5 17 ----- 2 -- 10 9 ----- 19 1 2 -- 4 -- 7 1 4 -- 5 -- 8 ----- 15 ----- 11 ----- 31 5 19 58 14 ----- 17 ----- 9 ----- 2 ----- 10 20 43 13 61 ----- 26 1 3 -- 1 3 -- 5 11 ----- 1 2 -- 4 -- 5 1 5 -- 1 2 -- 5 8 -- 1 -- 3
  • 13. A n swe r s 635 answers ➔ 9 a k 2 b a −5 c m ≤ 1 d x 5 e y ≥ 7 f d −2 g p ≥ − h x ≥ −5 i m −2 j a 9 k p ≥ 3 l x −4 Exercise 5H — Rearranging formulas 1 a = -- b = ----------- y – b y + b x x c x = -------------- 1 d x = e x = f x = ----------- ----------- ----------- 4y + 1 g x = h x = i x = −5y − 12 --------------- 5a – 9 19 j x = 12a k x = l x = ------ 5( f – 32) 2 a P = b c = c c = --------------------- ----------------------- ----------- b2 – d --- v – u d I = e t = f c = g y = hm + k h y = m(x − b) + a i a = y − m(x − b) j x = k r = -------------- ------------------------- C --------------- 2(s – ut) l x = m a = n G = 3 500 km 4 Maths Quest challenge (page 195) 1 51 2 9 3 17 Summary 1 pronumeral, equals sign, one 2 left-hand side 3 by itself 4 reverse order 5 cross-multiply 6 single 7 expand 8 portion 9 reversed 10 subject 11 formula, other pronumerals Chapter review 1 b, c, f, g, i 2 a 2x = 3 − x b 3x + 8 = 19 c 6x = 4 d − 1 = -- e 7(2x + 5) = 0 f 2x = 100 + x + 50 3 a y = 13 b y = 19 c y = 22 d y = −1 e a = −12.8 f a = 0.9 g a = 2.8 h a = −0.6 i b = −2.52 j b = 3.1 k b = −3.45 l b = 0.749 4 a x = 2 b x = −2 c x = 4 --------- d x = −21 e x = 3 f x = 18 g x = −2 h x = 15 i x = 19 j x = 13 k x = −6 -- l x = 1 1 m x = 6 n x = −8 o x = −11.13 5 a x = −2 b x = −1 c x = d x = 3 e x = 3 f x = 5 g x = 2 h x = −1 i x = 7 6 a x = 3 b x = 2 c x = 1 -- 1 -- d x = −1 e x = −12 f x = −8 -- 1 7 a 8h + 21 = 45 b 3 hours 8 600 km 9 a x = b x = 6 c x = − -- 3 d x = 1 e x = 12 f x = 1 10 a x = b x = 22 -- c x = 2 d x = 5 e x = 3 f x = − ----- -- -- 16 ----- 11 a x 4 b x ≥ c x −2 d x −14 e x ≤ −2 f x −1 g x ≥ 24 h x −8 i x − j x ≥ k x ≤ −7 l x −1 m x ≤ −3 n x ≤ −4 o x p x ≤ 7 q x −10 r x ≥ 1 -- -- 2 -- -- ----- ----------- q – 2r 12 a x = b x = c P = + 1 ----------- 2s d w = e a = f t = -------------- g a = h b = Chapter 6 Surds Are you ready? 1 a b c 2 a 0.8 b 0.375 c 0.8875 3 a b 12.7 c 4 a b c 5 a 8 b 5 c 3 d 2 e 3 f 1 6 a 2.45 b 0.3 c 7.105 d 0.71 e 15.290 f 73.1 7 a 4x − 32 b 6x + 3 c −20x − 45 8 a x2 − 49 b 3x2 − x − 10 c 4x2 − 12x + 9 Exercise 6A — Rational numbers 1 a 0.75 b 0.4 c 0.9 d 0.625 e 0.66 f 0.275 g 0.9125 h 0.3125 i 0.52 j 0.45 k 0.57 l 0.08 2 a b c d e f g h 3 a b c d e f g h i j k l 2 3 -- 6 7 -- 1 2 -- y a a 2a y + 7 2 ----------- 8 – 6y 5 y – 2 y + 1 y – 2 5 --------------- 14a + 13 93 g + 3 4 ------------ 5 f 9 9 V R a 4a y – a + mb m 2π ------ f – by a t2 --------------------- Fr2 Mm 50 4π –π ------------------ ≈ 11.92 cm 10 x ----- x 6 1 2 -- 3 4 -- 1 -- 5 1 3 -- 5 2 3 -- 1 2 -- 1 5 -- 5 7 4 5 12 ----- 1 2 2 1 2 -- 1 5 14 2 9 -- 1 6 6 7 -- 1 2 3 8 21 5 6 -- 1 5 -- 1 3 5 2 5 -- 1 2 1 2 -- 7 12 y + 4 6 ----------- y – c m 2 P – 2l 2 -------------- v – u t u + v ----------- v2 – u2 2s ---------------- ------------------- 2A – ah h ----- 6 -- 5 2 9 12 -- 7 0.35 5.14-- 3 ----- 7 -- 5 5 20 8 ˙ 2 ˙ 7 0.3 ˙ 0.16 ˙ 0.32 0.785 ˙ 0.594 0.125 125 1 0.375 46 0.814 35 0.6 ˙ 0.27 0.8 ˙ 0.27 ˙ 0.83 ˙ 0.142 857 0.916 ˙ 0.06 ˙ 0.90 0.2916 ˙ 0.56 ˙ 0.259 5D 6A
  • 14. 636 A n swe r s answers 4 a B b D c C d C e D 5 a -- b ----- 3 c ----- 7 d -------- 67 e 19 ----- f g h i j k l 6 a b c d e f g h i j k l 7 a C b A c C d D History of mathematics — Richard Dedekind 1 Carl Gauss 2 Dedekind cuts 3 Writings on the work of other mathematicians Exercise 6B — Irrational numbers 1 a Surd b Not a surd c Not a surd ----- 357 -- 27 ----- 7 -- 3 ----------- -------- 29 ----- ----- 7 ----- 71 -- 28 -- 2 ----- -------- 379 ----- 109 ----- 5 ----- 17 -------- -------- 725 -------- d Surd e Surd f Surd g Not a surd h Not a surd i Surd j Not a surd k Surd l Not a surd 2 a C b D c A d D e D 3 a Rational b Irrational c Rational d Rational e Rational f Rational g Rational h Rational i Rational j Irrational k Rational l Irrational 4 a 8.185 b 9.055 c 12.124 d 2.285 e 2.627 f 0.868 g 50.339 h 44.294 i 24.653 j 94.526 k 3.473 l 18.846 5 a 2.844 b −9.637 c 4.019 d 5.983 e 5.059 f 1.052 g 1.424 h −3.363 i −2.431 j 0.9422 6 a 23 b 15 c 15 d −13 e 10 7 a A b C c D d C 8 a 56.37 b −9.48 c −1.05 d 0.51 e 28.08 f 2.02 9 a Rali’s answer is approximate, Tig’s answer is exact, so the teacher is right. b c -------- d Rali: 39600, Tig: 40 000 e 400 f The difference between and 0.33 is only , but has much more significance if taken over a larger amount. 10 a cm or cm b 14.1 cm 11 or approximately 4.9 m Maths Quest challenge (p. 208) 1 A recurring decimal has a pattern of numbers that recur. We can multiply the decimal by a power of ten, like 10, 100, 1000 …, and shift the pattern before the decimal point. Subtracting leaves just the whole numbers and then by division the decimal is expressed as a fraction with q ≠ 0 (refer to worked example 2 on page 202). 2 Squaring both sides gives 2 = . So p2 = 2q2. But this implies p2 is divisible by 2, therefore p must be divisible by 2. Let p = 2m. Now p2 = 4m2. Therefore q2 = 2m2. This implies that q2 is divisible by 2. 2m Therefore let q = 2n. Now --- = ------- . This contradicts our assumption that was in simplest form. Therefore, cannot be a rational number, therefore is irrational. 10 Quick Questions 1 1 0.325 2 3 4 5 6 Rational 7 Rational 8 Irrational 9 Rational 10 Irrational Exercise 6C — Simplifying surds 1 a b c d 7 e f g h i j k l m n o p q r s t 2 a b c 48 d e f g h i j 3 a b c d e f g h i j 4 a D b A c C d C e D f D g D h B 5 a b c d e f g h 6 a m b m c ≈ 6.804 m 7 a cm b 224 cm Exercise 6D — Addition and subtraction of surds 1 a b c d 0 e f g h i j k l m n o p q r 2 2 a b 0 c d e f g h i j k l m n 3 a D b A c C d A 4 5 10 50 100 20 3 4 25 8 40 1000 221 250 80 5 9 3 33 99 15 2 11 90 18 300 990 616 999 999 33 100 -------- 1 300 1 3 -- 0.003 ˙ 200 10 2 2 6 p q --- p2 q2 ----- p q 2n p q --- 2 2 0.16 ˙ -- 7 5 8 -- 9 127 495 -------- 2 5 2 2 3 2 30 5 2 2 7 6 3 12 2 4 3 10 5 9 2 2 13 55 2 21 7 2 11 3 7 7 78 4 10 4 2 15 3 35 2 20 6 10 3 4 42 72 2 27 5 132 2 12 175 108 80 384 90 32 720 600 338 15 3 19 5 16 7 17 2 a c d2 b hk j f f 3 2 3 3 12 – 3 3 60 14 2 2 –4 5 –6 3 5 11 2 7 10 2 + 7 3 8 5 + 6 8 10 + 7 3 16 2 – 11 5 2 6 5 5 + 15 8 7 – 11 11 – 2 7 – 13 3 6 – 4 3 5 2 – 6 7 2 –5 3 –4 7 5 6 + 6 5 2 3 – 3 5 4 6 + 6 5 – 14 2 29 5 + 22 3 9 11 – 30 28 2 – 39 5 69 3 – 17 2 18 10 + 42 2 69 – 51 2 41 5 + 6 3 – 6 2
  • 15. A n swe r s 637 answers ➔ 4( ) cm 5 a 67 m b m c m d 10.39 m Exercise 6E — Multiplication and division of surds 1 a b 5 c −5 d e f 8 g −10 h i j k l 24 m −150 n o −168 p q 1250 r s t u 2 a D b C c A 3 a b c d e f g h 4 i j k l ------ 1 m n 15 o −8 p ----- 3 ----- 13 q 1 r 1 s t ------ -- 4 a B b C c C d D 5 a 1 b 1 c 1 d 1 6 a b c -- 3 -- 1 -- 1 d e f g h i j k l m 12 n o p −15 q r 7 a b c −1 d 2 e f g h i -- 8 a 42 b cm c cm d cm2 e 42 9 ( + )2 = 2 + 2 + 3 = 5 + 2 but ( )2 = 5 10 a m b 10 Quick Questions 2 1 2.25 2 3 4 5 4.05 6 2 7 8 9 10 Exercise 6F — Writing surd fractions with a rational denominator 1 a ------ b ------ 5 c ------ 6 d 7 --------- 30 e f g h --------- 30 --------- 6 ------ 15 2 a b c d ------------- 3 10 ------------- 6 e f g h --------- 70 i j k l ------ --------- --------- ------ --------- ------------- 2 6 ---------- 5 3 a b c d 4 a b c d 5 a b 6 a b c d e f or 5 − g h or 27 + Maths Quest challenge (p. 229) 1 8, 18, 50 (other answers possible) 2 a 177 768 889 b 399 9660 001 c 16 Summary 1 decimal 2 repeater 3 rational 4 recurring 5 power 6 fractions 7 surds 8 approximation 9 perfect 10 factor 11 like 12 multiplied Chapter review 1 a 0.08 b 0.8125 c d 2 a C b D 3 a b c d e 4 a Rational b Rational c Irrational ------ ------ 2 3 ---------- 2 ------ --------- 15 ------------------------------------------ 15 3 -- 83 -------- 5 -- 83 d Rational e Irrational f Rational ----- 5 = -- exactly but 15 cannot be expressed as a fraction. 6 a 7.9 b 13.7 c 0.5 d 25.7 7 a b 51 cm 8 a b c d 9 A 10 a b c d 11 a b c 12 D 13 a b c 13 d e3 f 40 + 5 2 + 2 13 (31 + 4 41) (36 – 4 41) 5 5 35 – 66 2 15 2 14 6 2 15 2 24 5 6 2 108 2 1600 2 28 7 12 15 3 2 5 2 15 3 5 –2 5 9 3 –2 2 2 2 ------ 3 4 6 4 45 32 4 3 ---------- 2 5 2 3 6 2 4 3 2 + 3 5 5 6 – 5 2 6 5 + 6 11 8 2 + 24 4 7 – 20 10 – 2 2 42 + 7 7 6 + 15 2 5 + 2 10 42 – 8 14 5 + 2 5 6 – 5 6 60 – 18 5 12 14 + 8 35 50 – 15 2 8 6 – 60 2 10 – 15 + 2 6 – 3 3 35 – 14 + 3 10 – 2 7 + 10 27 + 2 6 8 – 2 15 5 + 2 6 42 – 24 3 4 2 168 2 504 2 2 3 6 6 5 3 2 18 2 m2 0.45 7 ----- 99 11 3 10 16 2 40 2 3 3 ------ 3 3 5 6 7 10 5 --------- 5 15 5 5 15 5 6 3 5 2 6 3 ---------- 2 21 7 5 2 30 6 30 2 2 2 15 7 ------------- 2 42 3 5 4 2 2 3 2 2 3 2 2 ---------- 2 5(2 + 3) –2(1 – 2) 4( 5 – 2) 3(3 + 7) 3( 5 + 2) 5( 5 – 3) 15 2( 7 + 2) 3 6(3 6 + 5 2) 2 0.285 714 0.5 ˙ 4 5 -- 8 9 100 6 99 16 4 1 2599 3 11 5 7 24 2 12 10 150 180 605 18 4 6 – 7 5 3 18 5 – 6 7 5 2 24 21 –2 6 1 -- 2 30 6 --------- 6B 6F
  • 16. 638 A n swe r s answers 14 a 240 b 73 – 40 3 15 C 16 B 17 a ------ 7 b 5 6 c d 14 Chapter 7 Right-angled trigonometry Are you ready? 1 a 30° b 58° 2 a 4.74 b 18.5 c 0.378 d 507.182 e 10.80 f 0.7643 3 a x = 12 b x = 13.05 c x = 3.444 16 4 a x = 24 b x = 0.36 c x = 540 5 a 6.9 cm b 25.1 cm 6 a Isosceles b ∠ABC = ∠ACB = 45° c 2.83 cm 7 a East b South; west c C d B e Southwest Exercise 7A — Naming the sides of a right-angled triangle 1 a b ---------- 5 – 2 30 + 3 3 6 Adj. Hyp. Opp. θ c d Hyp. Adj. Opp. θ e f Opp. Hyp. Adj. Opp. Hyp. Adj. Opp. Opp. θ Hyp. Adj. θ 2 a DE = hyp DF = opp ∠E = θ b GH = hyp HI = adj ∠H = θ c JL = hyp KL = opp ∠J = θ 3 a Adj. θ Hyp. b ≈ 0.86 c ≈ 0.87 d ≈ 0.86 4 a b 0.86 c 0.86 5 a b 1 c 1 6 D 7 a D b A, C c C Maths Quest challenge (page 243) Exercise 7B — Trigonometric ratios 1 a i sinθ = ii cosθ = iii tanθ = --- e --- d -- i -- h b i sinα = ii cosα = iii tanα = -- l -- j c i sinβ = ii cosβ = iii tanβ = ---- n d i sinγ = ii cosγ = iii tanγ = -- b e i sinβ = ii cosβ = iii tanβ = -- v f i sinγ = ii cosγ = iii tanγ = 2 a sinθ = b cosθ = c tanθ = ----- 4 ----- 25 d sin 15° = e tanθ = f cosα = ----- 3.1 g tanθ = h sin 35° = i sinα = 3 a ----- 14.3 41° b O = 34 mm A = 39 mm H = 51 mm c i sin 41° = 0.67 ii cos 41° = 0.76 iii tan 41° = 0.87 d α = 49° e i sin 49° = 0.76 ii cos 49° = 0.67 iii tan 49° = 1.15 -- -- -- -- -- -- -- ------- ---------- f They are equal. g They are equal. h The sine of an angle is equal to the cosine of its complement angle. 4 a 25° b O = 23 mm A = 50 mm H = 55 mm Triangle Angle Opposite side Hypot-enuse θ Sine ratio i ΔMNO ∠M = 60° 26 mm 29 mm 0.86 ii ΔPQR ∠P = 60° 30 mm 35 mm 0.86 iii ΔSTU ∠S = 60° 18 mm 22 mm 0.86 Triangle Angle Adjacent side Hypot-enuse Cosine ratio i ΔMNO ∠M = 30° 26 mm 30 mm 0.87 ii ΔPQR ∠P = 30° 37 mm 43 mm 0.86 iii ΔSTU ∠S = 30° 51 mm 59 mm 0.86 Triangle Angle Opposite side Adjacent side Tangent ratio i ΔMNO ∠M = 45° 24 mm 24 mm 1 ii ΔPQR ∠P = 45° 33 mm 33 mm 1 iii ΔSTU ∠S = 45° 45 mm 45 mm 1 25 5 15 30 10 20 e f f d i g g h l k k j n m ---- o m o b c -- a c a v u -- t u t 12 15 30 5 7 x -- 20 31 9.8 2.7 p ------- 17 t 17.5 H O A α H O A β
  • 17. A n swe r s 639 answers ➔ c i sin 25° = 0.42 ii cos 25° = 0.91 iii tan 25° = 0.46 d β = 65° e i sin 65° = 0.91 ii cos 65° = 0.42 iii tan 65° = 2.17 f They are equal. g They are equal. h The sine of an angle is equal to the cosine of its complement angle. 5 a 45° b O = 41 mm A = 41 mm H = 58 mm c i sin 45° = 0.71 ii cos 45° = 0.71 iii tan 45° = 1.00 d γ = 45° e i sin 45° = 0.71 ii cos 45° = 0.71 iii tan 45° = 1.00 f They are equal. g They are equal. h The sine of an angle is equal to the cosine of its complement angle. 6 a D b B c A d D Maths Quest challenge (page 248) Exercise 7C — Finding trigonometric ratios using a calculator 1 a 0.7314 b 0.9613 c 1.2349 d 0.9962 e 28.6363 f 0.9063 g 0.5774 h 0.9903 i 0.1392 j 0 k 0.5150 l 0.9325 2 d i 0.5736 ii 0.8192 iii 0.7002 Exercise 7D — Finding side lengths 1 a 13.02 m b 7.04 m c 27.64 mm d 2.79 cm e 6.27 m f 14.16 m 2 a 2.95 cm b 25.99 cm c 184.73 cm d 14.06 km e 8.43 km f 31.04 m 3 a 26.96 mm b 60.09 cm c 0.84 km d 0.94 km e 5.59 m f 41.67 m g 54.73 m h 106.46 cm i 298.54 mm 4 21.32 m 5 285.63 m 6 5.80 km 7 a D b B c A Maths Quest challenge (page 254) About 62° Exercise 7E — Angles and the calculator 1 a 0.500 b 0.707 c 0.466 d 0.839 e 8.144 f 0.719 2 a 0.65 b 0.59 c 0.52 d −1.50 e 1.00 f 0.67 g 0.81 h 0.53 i −0.80 j 0.41 k 0.99 l −0.96 m 1.73 n −0.57 o 0.13 3 a 50° b 24° c 53° d 71° e 86° f 41° 4 a 54°29′ b 6°19′ c 0°52′ d 72°47′ e 44°48′ f 26°45′ 5 a 26°33′54′′ b 64°1′25′′ c 64°46′58′′ d 48°5′22′′ e 36°52′12′′ f 88°41′27′′ 6 a 2.824 b 71.014 c 20.361 d 2.828 e 226.735 f 1.192 g 7.232 h 32.259 i 4909.913 j 0.063 k 0.904 l 14.814 Maths Quest challenge (page 258) 1 a b c 2 Any multiple of 3 (extension of part b) or power of 2 (extension of parts a and c). 10 Quick Questions 1 1 sinβ = 2 0.4067 3 0.675 4 cosθ = 5 0.54 m 6 17.11 mm 7 45.9 cm 8 63.34 cm 9 59.14 cm 10 2.6 m Exercise 7F — Finding the size of an angle 1 a 67° b 47° c 69° 2 a 54°47′ b 33°45′ c 33°33′ 3 a 75°31′21′′ b 36°52′12′′ c 37°38′51′′ 4 A, B, C 5 a 41° b 30° c 48° 6 a a = 25°47′, b = 64°13′ b d = 25°23′, e = 64°37′ c x = 66°12′, y = 23°48′ 10 Quick Questions 2 Exercise 7G — Problems involving two right-angled triangles 1 a a = 15 θ = 37° β = 56° b x = 13.86 y = 40.52 c x = 30° y = 56° z = 30 d x = 56 y = 48.50 e x = 12.77 y = 4.37 θ = 41° f x = 11.65 y = 24.45 θ = 39° g w = 11.34 x = 11.33 y = 11.34 z = 54.04 h a = 90.46 b = 15° c = 93.85 if Pythagoras’ theorem used or c = 96.59 if sin 15° is used. 2 z = 5.36 m, x = 4.50 m, y = 2.82 m, Area = 19.62 m2 3 111.87 km Exercise 7H — Applications 1 a 36°52′ b 53°8′ c 2.4 m 2 a 14°29′ b 31 cm 3 8.74 m 4 687.7 m 5 a 176.42 m b 152.42 m H O A γ b c -- -- y z 1 3.2472 2 78° 3 74°58′ 4 10.6 5 13.5 m 6 41° 7 422 m 8 35°53′ 9 7.34 cm 10 26°33′54′′ 7A 7H
  • 18. 640 A n swe r s answers 6 23.88 cm 7 a 56.83 cm b 62.50 cm 8 65°46′ 9 6.09 m 10 19°28′ 11 62°33′ 12 16.04 m 13 a 54° b 0.75 m 14 a h = x tan 47°12′ h = (x + 38) tan 35°50′ b x = 76.69 m c 84.62 m 15 a h = x tan 43°35′ h = (x + 75) tan 32°18′ b 148.37 m c 143.1 m 16 a 11°32′ b 4°25′ 17 a iii 35.36 cm ii 51.48 cm iii 51.48 cm iv 57.23 cm v 29°3′ vi 25°54′ b iii 25.74 cm ii 12.5 cm iii 25°54′ iv 28.61 cm 18 a 77° b 71°56′ c 27.35 cm 19 a 7.05 cm b 60°15′ c 8.12 cm 20 a 28.74 cm b 40.64 cm c 66°37′ 21 a 26.88 cm b 11.07 cm Maths Quest challenge (page 274) 1 39 2 0 Exercise 7I — Bearings 1 a 020°T b 340°T c 215°T d 152°T e 034°T f 222°T 2 a N49°E b S48°E c S87°W d N30°W e N86°E f S54°W 3 a 3 km 325°T b 2.5 km 112°T c 8 km 235°T d 4 km 090°T, 2.5 km 035°T e 12 km 115°T, then 7 km 050°T f 300 m 310°T, then 500 m 220°T 4 a b N c d e N 180 km 5 a iii 13.38 km ii 14.86 km iii 222°T b iii iii 51.42 km iii 61.28 km iv 310°T c iii iii 38.97 km iii 22.5 km iv 030°T 6 215°T 7 A 8 1.732 km 9 a 9.135 km b 2.305 km c 104° 10′T 10 684.86 km 11 B 12 a 60°43′T b 69°27′T c 204°27′T History of mathematics 1 A mountain 2 Great Trigonometric Survey of India 3 Leveller, zenith sector, telescope, chronometer, large theodolite Summary 1 angle 2 hypotenuse, opposite, adjacent 3 sinθ = 4 cosine ratio 5 opposite side (O) to the adjacent side (A) 6 SOH–CAH–TOA 7 length 8 two 9 inverse 10 trigonometric inverses 11 angle of elevation 12 angle of depression 13 north–south 14 clockwise Chapter review 1 a b c Adj θ 2 a cosθ = b tanβ = c sinγ = 3 B, C 4 a 0.8090 b 0.7771 c 0.2126 5 a 7.76 b 36.00 c 2.56 m ----- 11 ----- d 19.03 e 6.79 km f 394.29 mm 6 32.33 cm 7 7.78 m 8 1.44 m 9 B 10 B 11 a 9° 03 b 33° 16 c 27° 38 12 A 13 a 32° b 45° c 39° d 52° e 68° f 30° g 60° h 60° i 83° 14 a 49° b c 15 s = 41.69 t = 16.84 16 α = 74°27′ β = 27°25′ 40° 100° N 30 km 40 km 240° 135° N N 230 km 140 km 120° 260° 32° N N N 0.8 km 1.3 km 2.1 km 50° 30° 40° S N N 8 km 5 km 7 km 30° 70° 20° N S 320 km 220 km 42° 130° N N 80 km 20 km A B C 42° 130° 210° N N N 80 km 20 km 45 km A B D C O ---- H θ Hyp Opp Adj Opp Hyp θ Hyp Opp Adj 6 7 -- 12 5 13 ′ ′ ′ 60°4′ 36°52′12′′
  • 19. A n swe r s 641 answers ➔ 17 74° 24 ′ 18 0.033 km or 33 m 19 a 10°38′ b 6°26′ 20 21° 21 a 346°T b 156°T c 217°T d 048°T 22 a S52°E b N66°W c N34°E d S38°W 23 67.98 km 24 4.16 km 25 5 8 θ 26 Approx 45° Chapter 8 Collecting and organising data Are you ready? 1 3 4 5 6 7 8 9 10 11 12 2 Key: 2 | 3 = 23 Exercise 8A — Dot plots and stem-and-leaf plots 1 a b The scores lie between and include 6 to 20; that is, a range of fourteen. Mostly between 16 to 18 packets were sold. Sales of 6 and 20 packets of chips were extremely low. A provision of 20 packets of chips each day should cover the most extreme demands. 2 a b c d 0 1 2 3 4 5 18 19 20 21 22 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 6.0 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 3 Check with your teacher. 4 Key: 1 | 7 = 17 The youngest participant is 17, the oldest is 45. The aerobics class was most popular among participants in their late teens and 20s. Stem Leaf 12345 0 9 7 3 3 4 8 5 6 2 3 Score Tally Frequency 1 III 3 2 III| 5 3 II|| || 7 4 IIII 4 5 II 2 6 III 3 4 Score Frequency 20 5 21 8 22 7 23 2 24 4 6 7 8 9 10111213 14151617181920 Stem Leaf 1234 7 7 8 8 8 9 9 1 1 2 3 3 4 6 8 0 1 1 1 5 5 a Key: 1 | 8 = 18 b Key: 1 | 9 = 19 Stem Leaf 12 8 9 9 0 0 0 1 1 2 Stem Leaf 1234 9 9 0 4 4 5 6 7 9 1 1 6 8 2 3 c Key: 33 | 6 = 336 Stem Leaf 33 34 35 36 37 6 6 6 9 0 3 9 2 8 1 d Key: 4 | 3 = 43 Stem Leaf 45678 3 4 6 7 8 9 2 5 7 0 7 1 2 3 3 4 5 8 e Key: 1 | 1 = 1.1 Stem Leaf 1234 1 3 5 9 4 7 8 9 3 6 9 1 2 6 6 a Key: 1* | 8 = 18 2 | 0 = 20 b Key: 1* | 9 = 19 2 | 0 = 20 Stem Leaf 1* 2* 8 9 9 0 0 0 1 1 2 Stem Leaf 1* 2* 2* 3* 3* 4* 9 9 0 4 4 5 6 7 9 1 1 6 8 2 3 7I 8A
  • 20. 642 A n swe r s answers c Key: 33* | 6 = 336 35 | 0 = 350 e Key: 1 | 1 = 1.1 1* | 5 = 1.5 Stem Leaf 1* 1* 2* 2* 3* 3* 4* 4* 1 3 5 9 4 7 8 9 3 6 9 1 2 6 7 a See answer at bottom of page. b Discuss in class. c Key: 10 | 0 = 10.8 d Range = 4.2 Discuss in class. e Discuss in class. f Discuss in class. 8 a Key: 6 | 3 = 63 b See answer at bottom of page. c Discuss in class. d Discuss in class. 9 Key: 0 | 1 = 1 Mitch scored between 0 and 3 goals inclusive. Yani scored between 0 and 2 goals inclusive. 10 a Mitch: 2, Yani: 3 b Mitch c Yani: 11 d Yani, as he scored goals in more games. 11 a Key: 3 | 2 = 32 b 9A: 83%, 9B: 92% c 9A: 2 d Discuss in class. e Discuss in class. f 9A: 64.3; 9B: 68.5 g See answer at bottom of page. h Discuss in class. 12 a C b D 10 Quick Questions 1 1 12 2 18 3 16 4 13, 15 and 18 5 20 6 9 7 48 8 30 9 28 and 39 10 Stem Leaf 10 11 12 13 14 15 8 9 0 2 5 8 0 4 5 6 8 8 2 6 6 9 9 0 1 0 Stem Leaf 6789 3 6 7 8 9 0 0 1 4 5 6 7 8 9 1 2 3 6 6 7 8 9 3 8 d Key: 4 | 3 = 43 4*| 6 = 46 Stem Leaf 33* 34* 34* 35* 35* 36* 36* 37* 6 6 6 9 0 3 9281 Stem Leaf 4* 4* 5* 5* 6* 6* 7* 7* 8* 8* 3 4 6 7 8 9 25 707 1 2 3 3 4 5 8 Leaf Leaf (Mitch) 3 2 1 1 1 1 0 0 0 0 Stem 0 (Yani) 0 0 1 1 1 1 1 2 2 2 Leaf Leaf (9A) 29 7 4 8 7 5 5 0 356 Stem 3456789 (9B) 65 0 2 8 3 3 4 5 7 8 1 Key: 1 | 2 = 12 1* | 6 = 16 Stem Leaf 0* 9 1* 1* 6 7 9 2* 1 1 3 3 4 2* 6 6 7 8 8 8 3* 2 2 3* 5 7 9 9 9 4* 0 1 3 4* 5 6 6 7 8 7 a 8 b 11 g 10.8 11.0 10.9 11.2 11.3 11.1 11.4 11.5 11.6 11.7 11.8 11.9 12.0 12.1 12.2 12.3 12.4 12.5 12.6 12.7 12.8 12.9 13.0 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 14.0 14.1 14.2 14.3 14.4 14.5 14.6 14.7 14.8 14.9 15.0 62 64 63 66 67 65 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 32 44 46 48 50 54 33 43 45 47 49 51 Percentages 52 53 34 35 36 37 38 39 40 41 42 56 57 55 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96
  • 21. A n swe r s 643 answers ➔ Exercise 8B — Displaying ungrouped data 2 3 4 a b c 6 5 4 14 12 10 18 16 14 12 10 b 2 c 15 d 18 6 7 Number of cars per household Number of jelly beans per pack 8 a Frequency column: 7, 10, 6, 4, 2, 1 b and c Number of hours of homework Maths Quest challenge (page 300) 1 Pattern is: two dots of the same colour produce a red dot in the row below; two dots of different colour produce a black dot in the row below. The last dot in the row is always black. 2 No, there must be a black dot at the end of each row. 3 No, as pattern starts to repeat in Row 9 and no rows have all black dots. 4 Yes Exercise 8C — Displaying grouped data 1 Score Tally Frequency 6 III 3 7 III 3 8 II 2 9 IIII I 6 10 III 3 11 III 3 12 III 3 13 I 1 Σf 24 5 a x Frequency 0 1 1 6 2 8 3 5 4 2 5 3 Total 25 3 2 1 6 7 8 9 1011 12 13 Frequency Score 0 Frequency 0 2 4 6 8 0 1 2 3 4 5 x Frequency 0 1 2 3 4 5 6 1 2 3 4 5 6 x Frequency 0 2 4 6 8 150 151 152 153 154 155 x Frequency 0 1 2 3 4 5 50 52 54 56 58 60 x 1 a Class interval Class centre Tally Frequency 5–10 7.5 | | | | | | | | | 11 10–15 12.5 | | | | | | | | | | | | | | | | 19 15–20 17.5 | | | | 5 20–25 22.5 | | 2 25–30 27.5 | | | 3 Total 40 0 1 2 3 4 5 10 5 Frequency Number of cars 48 50 52 30 20 10 Frequency Number of jelly beans 0 1 2 3 4 5 10 5 Frequency Number of hours d 1 Row 7 Row 8 Row 9 8B 8C
  • 22. 644 A n swe r s answers b b b c 16 e Heights of Year 9 students 157.5 Heights of Year 9 students 152.5 Discuss in class. b 20 18 16 14 12 10 2 Class interval Class centre Tally Frequency 0–4 2 | | | | | 6 5–9 7 | | | 3 10–14 12 | | | | | | | | | | 12 15–19 17 | | 2 20–24 22 | | | | | | | | 9 Total 32 3 a Class interval Class centre Tally Frequency 0–9 4.5 | | | | | 6 10–19 14.5 | | | | | | 7 20–29 24.5 | | | | | | | 8 30–39 34.5 | | | | 5 40–49 44.5 | | | | 4 50–59 54.5 | | | | | | | | | | 12 60–69 64.5 | | | | | | | 8 70–79 74.5 | | | | 4 80–89 84.5 | | 2 Total 56 12 10 Number of phone calls made per week 4 a Class interval 24.5 44.5 64.5 74.5 Class centre Tally Frequency 145–150 147.5 | | 2 150–155 152.5 | | | | 4 155–160 157.5 | | | | | | | 8 160–165 162.5 | | | | | | 7 165–170 167.5 | | | | 5 170–175 172.5 | | | 3 175–180 177.5 | 1 Total 30 Hours of TV watched per week Frequency 0 2 4 6 8 7.5 12.517.522.527.5 x Frequency 0 2 4 6 8 4.5 14.5 34.5 54.5 Number of phone calls 84.5 d Class interval 167.5 177.5 Class centre Tally Frequency 145–148 146.5 | 1 148–151 149.5 | | 2 151–154 152.5 | | 2 154–157 155.5 | | | | 4 157–160 158.5 | | | | 5 160–163 161.5 | | | | 4 163–166 164.5 | | | 3 166–169 167.5 | | | | 5 169–172 170.5 | | 2 172–175 173.5 | 1 175–178 176.5 — 0 178–181 179.5 | 1 Total 30 5 a Class interval 158.5 164.5 170.5 176.5 Class centre Tally Frequency 12–15 13.5 | | | | 4 16–19 17.5 | | | | | | 7 20–23 21.5 | | | | | | | | | 11 24–27 25.5 | | | | | | | | | | | 13 28–31 29.5 | | | | 4 32–35 33.5 — 0 36–39 37.5 | 1 Total 40 Frequency 0 1 2 3 4 5 6 7 8 147.5 152.5 162.5 172.5 Heights (cm) Frequency 0 1 2 3 4 5 146.5 149.5 155.5 161.5 167.5 Heights (cm) 173.5 179.5 Frequency 12 10 0 2 4 6 8 Mathsville class sizes 13.5 17.5 21.5 25.5 29.5 33.5 37.5 Class size
  • 23. A n swe r s 645 answers ➔ 6 a Frequency column: 3, 7, 8, 3, 3, 3, 2, 1 b Forearm length of boxers 24.5 25.5 26.5 27.5 28.5 29.5 30.5 31.5 7 a Frequency column: 2, 5, 8, 8, 5, 2 b, c 100 m sprint times 8 a Frequency column: 1, 2, 4, 6, 4, 2, 1 Fat content of packs of bacon b Frequency column: 7, 10, 3 10 8 Fat content of packs of bacon 10 Quick Questions 2 1 lowest score = 4, highest score = 10 2 19 3 9 5 11 6 0 17181920 8 15–17 9 10 The grouped data shows that the data is evenly spread while ungrouped data shows erratic changes. Exercise 8D — Cumulative frequency 1 Cumulative frequency column 3, 8, 16, 28, 38, 45. 2 3 a b 53 c 37 4 a 4 Score Tally Frequency 9 I 1 10 0 11 IIII 5 12 II 2 13 0 14 III 3 15 III 3 16 II 2 17 II 2 18 I 1 19 0 20 I 1 Σf = 20 87654321 Frequency Forearm length (cm) 10.75 11.25 11.75 12.25 12.75 13.25 8 6 4 2 Frequency Time (s) 0 4 8 1216 20 24 28 6 4 2 Frequency Fat content (%) 0 102030 6 4 2 Frequency Fat content (%) c The data appear more clustered if the group size is larger. 7 Class Class centre Tally Frequency 9–11 10 IIII I 6 12–14 13 IIII 5 15–17 16 IIII II 7 18–20 19 II 2 Σf = 20 x f cf 16 5 5 17 8 13 18 6 19 19 4 23 20 7 30 x f cf 0 17 17 1 15 32 2 21 53 3 10 63 4 21 84 5 16 100 x f cf 6 3 3 7 5 8 8 9 17 9 4 21 10 4 25 321 4 5 9 10 11 12 13 14 15 16 Frequency Score 321 4 5 6 7 10 13 16 19 Frequency Class centre 8C 8D
  • 24. 646 A n swe r s answers b c 5 6 a 50 45 40 35 30 25 20 b 27 c 13 d 70 e 7 a b c Temperatures of 90 summer days 12 11 10 Temperatures of 90 summer days 12 11 10 Frequency Score d 31 e 32 8 Frequency column 5, 8, 8, 14, 5 9 Score for mathematics quiz 44 40 36 32 28 24 20 16 12 10 0 11 Check with your teacher x f cf 8 5 5 10 7 12 12 9 21 14 8 29 16 11 40 Class f cf 1–5 8 8 6–10 14 22 11–15 14 36 16–20 5 41 21–25 9 50 Scores of 40 professional golfers Score Tally Frequency Cumulative Frequency 66 IIII 4 4 67 IIII III 8 12 68 IIII 5 17 69 III 3 20 70 IIII II 7 27 71 IIII 5 32 72 IIII II 7 39 73 I 1 40 Σf = 40 15 10 5 0 1 2 3 4 5 Cumulative frequency Score 40 36 32 28 24 20 16 12 84 66 67 68 69 70 71 72 73 Cumulative frequency Score Score Tally Frequency Cumulative Frequency 28 IIII IIII I 11 11 29 IIII IIII I 11 22 30 IIII IIII 9 31 31 IIII 5 36 32 IIII IIII 10 46 33 IIII I 6 52 34 IIII I 6 58 35 IIII III 8 66 36 IIII IIII II 12 78 37 IIII IIII II 12 90 Σf = 90 Score Frequency Cumulative Frequency 12 2 2 13 3 5 14 5 10 15 8 18 16 10 28 17 6 34 18 3 37 19 3 40 20 1 41 Σf = 41 1 2 3 4 5 6 7 8 9 28 29 30 31 32 33 34 35 36 37 Frequency Score 1 2 3 4 5 6 7 8 9 28 29 30 31 32 33 34 35 36 37 4 8 12 13 14 15 16 17 18 19 20 Cumulative frequency Score
  • 25. A n swe r s 647 answers ➔ Chapter summary 1 number line 2 numerical 3 Back-to-back 4 frequency table 5 score, tally 6 Σf 7 histogram, polygon 8 horizontal, vertical 9 classes 10 class centre 11 Cumulative frequency 12 ogive Chapter review 1 Scores are distributed to the lower end. 2 a Key: 2 | 9 = 29 b Key: 3 | 1 = 31 3*| 7 = 37 c Gives a better impression of the distribution because smaller classes give more detail. 3 Boys Girls Key: 15 | 4 = 154 4 a b b c b 1 2 3 4 5 6 7 0 1 2 3 4 5 14 12 10 c Key: 0 | 8 = 8 Stem Leaf 234 5 5 7 7 7 7 8 8 8 9 9 9 0 0 0 0 1 1 1 1 1 1 1 3 3 5 5 5 5 6 6 8 9 0 0 1 2 2 3 4 4 5 6 6 6 7 8 8 9 9 Stem Leaf 2* 3 3* 4 4* 5 5 7 7 7 7 8 8 8 9 9 9 0 0 0 0 1 1 1 1 1 1 1 3 3 5 5 5 5 6 6 8 9 0 0 1 2 2 3 4 4 5 6 6 6 7 8 8 9 9 Leaf Stem Leaf 6 9 8 7 4 9 7 4 0 2 13 14 15 16 2 8 0 1 2 4 5 8 8 0 Score Tally Frequency 8 | 1 10 ||| 3 12 |||| || 7 14 |||| || 7 16 ||| 3 18 | 1 Σf = 22 0 1 2 3 4 5 321 4 5 6 7 Sizes of dress sold 8 1012 14 16 18 Frequency Score 5 a x f 0 4 1 5 2 7 3 3 4 0 5 1 Σf = 20 6 a Class 4 5 Class centre Tally Frequency 0–9 4.5 || 2 10–19 14.5 ||| 3 20–29 24.5 |||| | 6 30–39 34.5 |||| 5 40–49 44.5 |||| |||| 9 50–59 54.5 |||| |||| |||| 14 60–69 64.5 |||| |||| 9 70–79 74.5 || 2 Σf = 50 Stem Leaf 01234567 44.5 64.5 54.5 8 9 6 6 9 4 4 4 7 7 8 4 5 8 8 8 3 4 4 6 6 7 7 9 9 0 1 3 3 4 5 6 6 7 7 8 8 8 9 0 1 2 2 4 4 5 5 8 1 9 Frequency 0 0 1 2 3 Number of pets Number of pets Frequency 0 2 4 6 8 4.5 14.5 24.5 34.5 Weekly earnings ($) 74.5 8D 8D
  • 26. 648 A n swe r s answers or Key: 0* | 8 = 8 2| 4 = 24 b 8 a Number of CDs owned b 11 c 9 9 a b 50 45 40 35 30 25 20 c 23 d 17 10 a 20 Number of lessons to achieve driver's licence b Class column, 0–20, 20–40, 40–60, 60–80, 80–100 11 C 12 Check with your teacher. Chapter 9 Congruence and similarity Are you ready? 1 a PR b BC c d 2 4 3 a b c 4 a b 5 a b Stem Leaf 0* 1* 1* 2* 2* 3* 3* 4* 4* 5* 5* 6* 6* 7* 7* 8 9 6 6 9 4 4 4 7 7 8 4 5 8 8 8 3 4 4 6 6 7 7 9 9 0 1 3 3 4 5 6 6 7 7 8 8 8 9 0 1 2 2 4 4 5 5 8 19 7 a Class Class Centre Tally Frequency f 30–39 34.5 IIII IIII IIII IIII IIII 25 40–49 44.5 IIII IIII IIII II 17 50–59 54.5 IIII IIII IIII 14 60–69 64.5 IIII IIII IIII IIII I 21 70–79 74.5 IIII IIII IIII IIII III 23 Σf = 100 25 20 34.5 54.5 44.5 74.5 64.5 Score Tally Frequency Cumulative Frequency 0 III 3 3 1 IIII III 8 11 2 IIII I 6 17 3 II 2 19 4 I 1 20 Σf = 20 15 10 5 Frequency Score (class centre) Score Tally Frequency Cumulative Frequency 15 II 2 2 16 IIII II 7 9 17 IIII 4 13 18 IIII II 7 20 19 III 3 23 20 II 2 25 21 IIII III 8 33 22 IIII 5 38 23 IIII 5 43 24 IIII II 7 50 Σf = 50 15 10 5 15 16 17 18 19 20 21 22 23 24 Cumulative frequency Score ∠PQR ∠BAC P P´ P P´ P´ P P P' P P´ P P' P' P
  • 27. A n swe r s 649 answers ➔ Exercise 9A — Congruent figures 1 a i and iii b i and iv c ii and iv 2 a ΔABC and ΔPQR, SSS or SAS b ΔABC and ΔLMN, SSS c ΔLMN and ΔPQR, SAS d ΔABC and ΔPQR, ASA e ΔABC and ΔLMN, RHS f ΔABC and ΔDEF, ASA 3 a x = 25° b x = 70°, y = 40° c x = 40°, y = 55° d x = 30°, y = 30°, z = 120° e x = 40°, y = 40°, z = 100° f x = 35°, y = 55° 4 a I and II b II and IV c I and II, III and IV 5 a Use SAS. b Use SAS. c Use ASA. d Use ASA. e Use SSS. 6 C and D 7 a x = 110°, y = 110°, z = 4 cm, w = 7 cm b x = 70° c x = 30°, y = 65° 8 The triangles will only be similar. They may have different side lengths. 9 Use SAS. 10 Corresponding sides are not the same. 11 Use RHS. Exercise 9B — Similar figures 1 a b c 2 a i and iii, AAA b i and ii, SSS c i and ii, SAS d i and iii, RHS e i and iii, SSS 3 a Triangles ABC and DEC b Triangles PQR and ABC c Triangles PQR and STR d Triangles ABC and DEC e Triangles ADB and ADC 4 ΔEDC, check with your teacher. 5 Check with your teacher. 6 a i 1.3 cm ii 2.6 cm b 2 7 a -------- = BC ------- = AC -------- b f = 9, g = 8 8 a Yes, scale factor = 2 b No c Yes, scale factor = 3 d Yes, scale factor = 1.5 e No 9 a i = 3 -- , h = 3 1 -- b j = 1.8, k = 4.53 10 a b B' C' B' C' 11 x = 4 12 x = 20°, y = 2 13 x = 3, y = 4 14 8 m 15 2.4 m 16 14.36 m 17 100 cm and 150 cm 18 a Yes, scale factor = 10, all sides in the equal ratio b No. The length increases 2 times but the width remains the same. 19 8 m 20 m = 4 cm, n = 1.5 cm 21 8 cm 22 a Show two sides with corresponding ratios equal and the included angle equal b Show two sides with corresponding ratios equal and the included angle equal Maths Quest challenge (page 335) 1 2 13.61 cm in this case. In general, the position of X can be found by construction as shown in the diagram. History of mathematics — Thales of Miletus 1 He proposed the first natural cosmology and pioneered the scientific method. 2 A solar eclipse. 3 Any two of the following: Any circle is bisected by its diameter. The base angles of an isosceles triangle are equal. The opposite angles of intersecting straight lines are the same. The angle subtended by the diameter of a circle touching the circle is a right angle. Two triangles are congruent if they have the same base and base angles. 10 Quick Questions 1 1 1.16 m 2 5 m 3 13 m 4 17 m 5 1.2 m 6 a = 70°, b = 12, c = 12, d = 70° 7 e = 19, f = 35° 8 a = 12 9 b = 14.2 10 c = 3 , d = 7 Exercise 9C — Area and volume of similar figures 1 a 900 cm2 b 67.5 cm2 c 855 mm2 d 102 cm2 e 5 m2 f 25 mm2 2 a 5400 cm3 b 337.5 cm3 c 1809 mm3 d 100 cm3 e 2.5 m3 f 1 mm3 3 SA = 384 cm2, V = 288 cm3 4 50 000 cm2 5 a 250 000 cm2 b 17.4 cm2 6 8 437 500 cm3 7 a 1 200 000 cm2 b 187.5 cm2 8 a 6.5 cm b 274.625 cm3 c 2 197 cm3 d 34.3 cm3 e 28.2 cm2 Quick Questions 2 1 EG, ST 2 a False b True 3 Use RHS 4 Use SAS 5 Use SAS 6 Use equiangular test 7 4:1 8 5:1 9 80 cm2 10 27:64 24 cm 6 cm 10 cm 1.25 m 2 m AB AD DE AE 1 3 3 4 3 5 A' 6 8 10 A' 1 4 -- or A B B' Wall X 2 3 -- -- 1 3 9A 9C
  • 28. 650 A n swe r s answers Exercise 9D — Transformation of points and figures 1 2 a b 3 –4 –3 –2 –1 1 2 3 4 B CB' C' A D' B' C' 3 a Centre of rotation: C, angle of rotation: 180° b Centre of rotation: B, angle of rotation: 90° c Centre of rotation: G, angle of rotation: 180° 4 5 3 6 a b c d 7 a P′(−2, −2), Q′(−1, 2), R′(2, −1), S′(2, 3) b P′(2, 2), Q′(1, −2), R′(−2, 1), S′(−2, −3) c P′(2, −2), Q′(−2, −1), R′(1, 2), S′(−3, 2) d P′(4, 2), Q′(3, −2), R′(0, 1), S′(0, −3) e P′(−2, −4), Q′(−1, 0), R′(2, −3), S′(2, 1) 8 a x b y 9 a b c d e B A' A' B' 10 a 3 b 12 cm c 3.5 cm d 9 11 a b cm2 12 C 13 a i (−1, 2) ii (−2, 3) iii (−1, 4) b x- and y-coordinates are swapped, the sign of the x-coordinate is changed (i.e. x′ = −y, y′ = x). c i (−y, x) ii (−n, m) iii (8, −2) iv (5, 3) v (−2, −7) d i (2, −4) ii (−5, 2) iii (2, −5) 14 –2 –4 15 a Side lengths and angles b Angles c Side lengths and angles d Side lengths and angles 16 B 17 P′(4, 0), Q′(4, 2), R′(5, 0) 18 a 200 b i 6.2 m × 6 m ii 5 m × 4.8 m c 31.44 m2 4 2 1 –1 R''' R'' R' R'''' R 0 DA' x y 2 2 1 1 3 –1 –2 –2 –1 B C A D D' A' x y 2 2 1 1 –1 –2 –2 –1 B A C C' B' A' x y 2 3 2 1 1 –1 –2 –1 B C A D C' B' D' A' x y 2 2 1 1 3 –3 –2 –1 –1 –2 e • A B D C A' B' D' C' • A B C A' B' C' • A C B' C' • A B D C D' C' A • B C A' B' C' 1 2 -- P --- 4 y 2 4 6 x –6 –6 –4 –2 6 4 2 • • • • • • • • K L M N K' L' M' N' y 1 2 3 4 5 6 x 3 2 1 Q P R Q' P' R'
  • 29. A n swe r s 651 answers ➔ Summary 1 Congruent 2 AAS, RHS, SSS, SAS 3 Similar 4 5 equal 6 equiangular, sides 7 ≡, ||| 8 rotations, reflections 9 translation 10 centre of rotation 11 axis of symmetry 12 enlargement 13 size, angles 14 image 15 area, volume Chapter review 1 a I and III, ASA or SAS b I and II, RHS 2 a x = 8 cm b x = 70° c x = 30°, y = 60°, z = 90° 3 a Use SAS. b Use ASA. 4 Corresponding sides are not the same. 5 a ∠P = ∠S, given angle O is common ∠R = ∠T, third angle in a triangle, AAA. Other answers possible. b OP = OR = OS = OT (all radii) c If two corresponding sides are equal, that implies that the third side should also be equal, given all corresponding angles are equal. 6 a Similar, scale factor = 1.5 b Not similar c Similar, scale factor = 2 7 a x = 48°, y = 4.5 cm b x = 86°, y = 50°, z = 12 cm c x = 60°, y = 15 cm, z = 12 cm 8 a ΔABC ||| ΔDEC b ΔABC ||| ΔDEC c ΔABC ||| ΔPQR 9 a Show 3 pairs of equal angles (AAA). b ΔABC ||| ΔEDC c -------- -------- AC BC dd = 5 cm, e = 4.5 cm = = -------- 10 5 m 11 5 m 12 a 10 m b 83° 13 a 3 b 10 cm c 15 cm d 81 cm2 14 a (4, −2) b (2, −3) c (4, −3) 15 a b c y 2 1 –1 y 2 1 –1 d e f y 2 1 –1 Q' y 2 y P' Q' 2 R' –2 –1 1 2 R' –2 –1 1 2 –1 Q' 16 B 17 y 2 S' R' –1 –1 R' S' Q' 18 a (−1, 0) b (−2, 0) c (0, −1) d (−1, −1) 19 1:6 20 1:4 21 400 cm2 Chapter 10 Coordinate geometry Are you ready? 1 a y = 7 b y = 1 c y = 11 2 a y = x + 4 b y = 3x − 2 3 y B 4 A 2 E 0 x –4 –2 2 4 –2 –4 –6 F C 4 a Graph C b Graph B 5 a y = x + 3 b y = x − 2 c y = 2x y 6 4 2 –4 0 x y 4 2 –4 0 x –2 y 4 2 –4 0 x –2 6 a 10 m b 5 cm Exercise 10A — Plotting linear graphs 1 a b image ------------------------------ length object length AB ED EC DC –2 –1 1 2 –2 x P Q S R P' Q' S' R' –2 –1 1 2 –2 x P Q S R Q' P' 1 R' S' –2 –1 1 2 –2 x P Q S R P' Q' –2 –1 1 2 –2 x P Q S R P' S' 1 –2 x P Q S R P' S' 1 –2 x P Q S R S' R' P S R Q P' x −2 −1 0 1 2 y 2 3 4 5 6 x −2 −1 0 1 2 y −8 −5 −2 1 4 x −2 −1 0 1 2 y 1 2 3 4 5 D –2 2 4 –2 y = x + 3 x −2 −1 0 1 2 y −4 −3 −2 −1 0 –2 2 4 –4 y = x – 2 x −2 −1 0 1 2 y −4 −2 0 2 4 –2 2 4 –4 y = 2x x −2 −1 0 1 2 y 1 2 3 4 5 x y y = x + 3 5 21 43 –3–2–10 1 2 3 –1 –2 y x −2 −1 0 1 2 y −7 −6 −5 −4 −3 x 21 –2–10 1 2 3 4 5 –1 –2 –3 –4 –5 –6 –7 y = x – 5 9D 10A
  • 30. 652 A n swe r s answers c d e f g h 2 a y = 0 b x = 0 3 a b c d e f g h i j k l x −2 −1 0 1 2 y −10 −5 0 5 10 y = 5x x y 10 8 6 42 –3–2–1 01 2 3 –2 –4 –6 –8 –10 x −2 −1 0 1 2 y 0 2 4 6 8 y = 2x + 4 x y 87 21 43 5 6 –3–2–10 1 2 3 –1 x −2 −1 0 1 2 y −4 −1 2 5 8 y = 3x + 2 x y 87 21 43 5 6 –3–2–10 1 2 3 –1 –2 –3 –4 x −2 −1 0 1 2 y −6 −4 −2 0 2 x –3–2–10 1 2 3 y = 2x – 2 y 21 –1 –2 –3 –4 –5 –6 x −2 −1 0 1 2 y −11 −7 −3 1 5 x –3–2–10 1 2 3 y = 4x – 3 y 4 6 2 –4 –6 –8 –10 –12 x −2 −1 0 1 2 y 8 5 2 −1 −4 y = –3x + 2 x y 87 21 43 5 6 –3–2–1 0 1 2 3 –1 –2 –3 –4 x −2 −1 0 1 2 y 0 1 2 3 4 y = x + 2 x y 2 3 1 –3–2––11 1 2 3 0 –2 –3 x −2 −1 0 1 2 y −6 −5 −4 −3 −2 x –2––11 1 2 3 4 0 y = x – 4 y 2 1 –2 –3 –4 x −2 −1 0 1 2 y −3 −2 −1 0 1 y = x – 1 x y 2 3 1 –3–2––11 1 2 3 0 –2 –3 x −2 −1 0 1 2 y 3 4 5 6 7 y = x + 5 x y 4 5 2 3 1 –5–4–3–2–10 1 x −2 −1 0 1 2 y −6 −3 0 3 6 y = 3x y 2 3 1 –3–2––11 1 2 3 0 x –2 –3 x −2 −1 0 1 2 y −14 −7 0 7 14 y = 7x y 4 6 2 –3–2–1 01 2 3 x –4 –6 x −2 −1 0 1 2 y −7 −3 1 5 9 –1 y = 4x + 1 y 4 6 2 –3–2 01 2 3 x –4 –6 x −2 −1 0 1 2 y −7 −5 −3 −1 1 –3–2––11 1 2 3 0 y = 2x – 3 y x 2 3 1 –2 –3 x −2 −1 0 1 2 y −11 −8 −5 −2 1 x –3–2––11 1 2 3 0 y = 3x – 5 y 1 –2 –3 –4 –5 x −2 −1 0 1 2 y = –2x y 4 2 0 −2 −4 x y 2 3 1 –3–2––11 1 2 3 0 –2 –3 x −2 −1 0 1 2 y 14 8 2 −4 −10 x y = –6x + 2 y 2 3 1 –3–2––11 1 2 3 0 –2 –3 x −2 −1 0 1 2 y 14 9 4 −1 −6 y = –5x + 4 x y 4 2 3 1 –3–2––11 1 2 3 0 –2
  • 31. A n swe r s 653 answers ➔ 4 a b y = 4 4 –3–2––11 1 2 3 0 c d 5 a b c d –3–2––11 1 2 3 0 6 a b –3–2––11 1 2 3 0 c d 7 a b c d x = –5 y –8 –6–4–20 2 –2––11 1 2 0 Exercise 10B — Gradient and y-intercept 1 a Positive b Positive c Negative d Positive e Zero f Negative 2 a 1 b −2 c 3 d −1 e −3 f −1 3 a i m = 1 ii b = −1 b i m = −2 ii b = 2 c i m = −3ii b = 0 d i m = 3 ii b = −3 e i m = −3ii b = 6 f i m = ii b = 4 4 a b 3 c d−1 e – f – -- 1 -- 3 g h– -- i 0 -- 1 5 a 3 b 1 c d e3 f 2 g −2 h 1 i -- -- 6 78 8 C 9 B 10 A, C 11 1.7 m 12 0.75 13 –0.23 Maths Quest challenge (page 374) 1 a 67 + 31 + 4 + 5 = 107, 46 + 24 + 19 + 17 = 106 b Total of the eight numbers is an odd number. 2 There are 6 pairs (a, b): (1, 16), (3, 13), (5, 10), (7, 7), (9, 4), (11, 1). 3 When the pairs of (a, b) coordinates are plotted, the points lie on a straight line. 10 Quick Questions 1 1 (−2, 1) 2 D 3 4negative 5 y = 6x + 3 6 y = −3x + 4 7 m = 2, b = 10 8 y = 0 9 10 y = 4x + 2 x y 2 3 1 –2 4 y = 1 x y 4 2 3 1 –3–2––11 1 2 3 0 –2 1 x y = –2 y 2 3 1 –2 –3 −2 x –3–2––11 1 2 3 0 y = –5 y 1 –2 –3 –4 –5 −5 x −2 −1 0 1 2 y = 3 y 3 3 3 3 3 x y 2 3 1 –3–2––11 1 2 3 0 –2 –3 x −2 −1 0 1 2 y = 2 y 2 2 2 2 2 x y 2 3 1 –3–2––11 1 2 3 0 –2 –3 x −2 −1 0 1 2 y −2 −2 −2 −2 −2 x –3–2––11 1 2 3 0 y = –2 y 2 3 1 –2 –3 x −2 −1 0 1 2 y −4 −4 −4 −4 −4 –3–2––11 0 1 2 3 x y = –4 y 21 –2 –3 –4 x y x = 1 2 3 1 –2 –3 3 y x = 3 x 2 3 1 –3–2––11 1 2 3 0 –2 –3 −2 −7 −7 x x = –2 y 2 3 1 –3–2––11 1 2 3 0 –2 –3 x x = –7 y 3 21 –8–7–6–5–4–3–2––11 1 2 0 –2 –3 y x 2 2 2 2 2 y −2 −1 0 1 2 x 2 3 1 –3–2––11 1 2 3 0 –2 –3 x = 2 y x = 5 x −5 5 5 5 5 y −2 −1 0 1 2 x 2 3 1 –1 1 2 3 4 5 0 –2 –3 x −5 −5 −5 −5 −5 y −2 −1 0 1 2 x 2 3 1 –2 –3 x 0 0 0 0 0 y −2 −1 0 1 2 x 2 3 1 –2 –3 x = 0 y 1 3 -- 1 2 -- 3 2 4 2 1 2 -- 7 8 3 4 2 13 3 ----- 2 3 -- 2 3 -- x −2 −1 0 1 2 y 10 7 4 1 −2 y 10 42 6 8 –4 –2 2 4 –2 –4 –6 –8 –10 x x 6 6 6 6 6 y −2 −1 0 1 2 y 2 –6 2 6 x 4 4 6 –2–2 8 –4 –4 –6 x = 6 10B 10B
  • 32. 654 A n swe r s answers Exercise 10C — Determining the equation of a straight line 1 a y = 2x − 1 b y = 3x + 4 c y = −x + 5 d y = −4x − 2 e y = x + 2.5 f y = x − 3 g y = – x − 1 h y = – x + -- 1 -- -- 3 -- 1 -- 2 a y = 4x b y = −x + 1 c y = − x − 2 d y = -- x + 1 -- 1 e y = 5 -- x + 7 -- 3 f y = − 3 x − 5 g y = – x − 3 -- h y = −7x − 41 3 a y = 2x b y = x + c y = 4 -- -- 1 -- d y = x − 5 e y = – x − f y = – x − g y = – x − h y = −10x + 51 ----- 40 -- 25 -- 6 ----- ----- 4 a y = x + 1 b y = 2x − 4 c y = − x − 2 d y = – x + 2 -- 5 a y = x + 1 b y = x + 4 c y = − x + -- 3 -- 1 -- 2 -- 7 d y = – x − ----- 6 a y = 2 b x = −4 c y = x d y = −4x − 4 -- 7 a C b D c C, D d A, C, D Exercise 10D — Sketching straight line graphs 1 a, d, e, f, i 2 a b (1, 7) c d (1, 2) e f g h i 3 D 4 B, C 5 a i (0, 1) ii (−2, 0) b i (0, 6) ii (12, 0) c i (0, 5) ii ( , 0) d i (0, 50) ii (−20, 0) e i (0, 2) ii Does not f i Does not ii (3, 0) e i (0, 2) ii exist f i exist 6 a (3, 0), (0, 3) b (−5, 0), (0, 5) c ( , 0), (0, 1) d (−4, 0), (0, 3) e (2, 0), (0, -- ) f (4, 0), (0, −2 2 -- ) g (2 -- , 0), (0, −5) h (−17 1 -- , 0), (0, 7) i (2, 0), (0, 3) j (0.375, 0), (0, 1.5) 10 Quick Questions 2 1 y = 4x + 2 2 y = 3x − 10 3 y = 1 − 2x 4 y = x + 1 5 y = 1 − x 6 -- 7 y = -- x + 5 -- 8 y = 2x 9 10 Exercise 10E — Graphs of linear inequalities 1 a b 1 2 -- 2 3 3 3 2 -- 1 5 7 2 3 2 -- 2 3 3 4 4 4 1 3 -- 1 3 3 2 2 3 7 7 3 3 8 3 -- 17 3 1 2 -- 2 3 1 3 -- 1 2 3 3 2 2 4 5 -- 14 5 7 2 -- y x 2 y (4, 4) x 1 y x y x –5 (1, –4) y x (1, –3) y x (1, 2) 4 y x (3, 1) 3 y x –2 (2, –3) y x 1 4 1 4 -- y x 3 3 y x 5 –5 1 2 -- y x 1 1–2 y x 3 –4 2 5 3 y 2 x 2–5 y x –2 4 2–3 1 2 2 y x 2 –5 1–2 y x 7 –171–2 y x 3 2 y x 1.5 0.375 1 3 -- 1 2 1 2 2 –7 7–6 x y –3 5 x y y 2 0 x y ≤ 2 y 0 x y ≥ 0
  • 33. A n swe r s 655 answers ➔ c d y e f y g h y i j y –2 0 x k l y m n y 4 0 x 2 a b y c d y –x 3 –3 0 x e f g h i j y k l y y 3 D 4 D 5 C 6 B 7 a b y c d y 4x + 4y ≥ 16 e f y 2 g h i i 1 k l m n 4 o p 0 x y –1 –1 y y 6 6 0 x 0 x y 0 y 0 x y ≥ –6 –6 0 x x ≤ 4 y 4 0 x x ≥ 0 0 x x –2 y x 1 1 0 x x 0 y x ≥ –1 0 x –1 0 x x 4 y –5 x ≤ –5 0 x –x 7 y –y ≤ 2 –7 0 x –2 0 x y 5 –x ≤ –5 0 x y 4 –y –4 y 0 x –3 –y ≥ 3 y 0 x –2 x + 2 0 y 3 y – 3 ≥ 0 0 x 0 x 8 x – 8 0 0 x 4 –x + 4 ≤ 0 5 y – 2 3 0 x 0 –8 –y – 6 ≥ 2 x y –2 4 0 x y – 2x ≥ 4 y 0 x –1 –1 y + x ≤ –1 0 x 4 4 0 y x y – x ≥ 0 0 x y ≤ – x + 2 y 2 0 x 7 –14 y 2x – 14 y x y 6x –24 0 –24 4 y x 21 y ≤ –7x +21 0 3 y x x + y 0 0 –1 y x y ≤ x +7 0 7 –7 y x x y –2 0 2 –2 y x y 12x –24 0 –24 2 y x 3y ≥ x + 12 0 –12 y –2y ≤ 4x +6 x 0 –1.5 –3 y x x – y 10 0 –10 10 y 0 x y x – 4 –4 4 10C 10E
  • 34. 656 A n swe r s answers q r y 0 x 2 –4 2y 4x – 8 s t 0 y x 1 2x – y –1 1–2 – u v y 6 0 x y + 2x – 6 ≤ 0 3 w x y 0 x –1 y 5 5x + 2y – 10 0 0 ≥ 0 x 9x + 9y + 9 –1 y z y 0 –4 2 4x – 2y ≥ 8 0 y 4 –4 y – x – 4 0 0 x 1–2 – y –2 2y + 8x + 4 ≥ 0 y 0 x 1 –3 9x – 3y – 9 0 y 2 –15x + 5y – 10 0 2–3 – 8 a B b c A d D Exercise 10F — Parallel lines 1 2 b, f; c, e 3, 4, 5 and 6 Answers will vary. 7 a y = 3x + -- 3 b y = − 5 -- x − 10 2 8 a 5x − y − 1 = 0 b x − 2y + 8 = 0 c 5x + 15y − 6 = 0 2 0 x 7 ----- 7 9 B 10 D 11 Answers will vary. Exercise 10G — Perpendicular lines 1 Answers will vary. 2 3 a, e; b, f; c, h; d, g 4, 5, 6 and 7 Check with your teacher. 8 D 9 B Maths Quest challenge (p. 396) 1 Zoe plus 15 friends (16 altogether) 2 5 different-sized squares Exercise 10H — Distance between two points 1 AB = 5, CD = 2 10 or 6.32, EF = 3 2 or 4.24, GH = 2 5 or 4.47, IJ = 5, KL = 26 or 5.10, MN = 4 2 or 5.66, OP = 10 or 3.16 2 a2 + 4b2 3 a2 + b2 3, 4, 5 and 6 Answers will vary. 7 a AB = 4.47, BC = 2.24, CD = 4.47, DA = 2.24 b AC = 5, BD = 5 c Rectangle 8 B 9 C, D 10 11 a (4, 1) b (1, 1) Exercise 10I — Midpoint of a line segment 1 1 -- 1 2 2 -- 1 1 2 -- 2 -- 1 -- 1 1 2 2 3 (−3, −10) 4 5 D 6 C 7 8 9 -- 1 2 -- 2 -- 2 1 2 -- Exercise 10J — Further equations of straight lines 1 y = 2x − 9 2 3x + 2y − 8 = 0 3 4 5 6 7 y = −x − 3 8 4x − 6y + 23 = 0 9 10 11 a A, D b C c C Summary 1 linear graph 2 y = mx + b 3 slope 4 m 5 y-intercept 6 b x x a No b Yes c No d No e Yes f No a Yes b Yes c No d Yes e Yes f No a 5 b 13 c 10 d 7.07 e 6.71 f 14.42 g 13 h 13 i j a 12 b 5 c 13 d −2.2 a (2, 5) b (3, 9 ) c (1, 6 ) d (5 , −7) a (−3, −3 ) b (7 , 0) c (−1, 1) d (0, 1 ) e (2a, b) f (a + b, a) a (3, 1) b 4.47 c 6.32 a i (−1, 4) ii (1 , 1) iii 3.9 iv 7.8 b Answers will vary. a i (1, −0.5) ii (1, −0.5) b Answers will vary. a i (−2, 2) ii 8.94 iii 9.55 iv 9.55 b Isosceles triangle, height. a y = 3x + 2 b y = −4x + 9 c 3x − 2y − 8 = 0 d 2x + 5y + 13 = 0 e x + 5y + 5 = 0 f x − 3y + 17 = 0 g x − 3y − 14 = 0 a 2x − y + 5 = 0 b x + 2y = 0 a 3x − 5y + 2 = 0 b 5x + 3y − 8 = 0 a (2, 5) b 1 c Answers will vary. d Isosceles triangle a y = −x + 5 b y = x + 3 c (1, 4) a 7x − 3y − 1 = 0 b 3x + 7y − 49 = 0 c −7
  • 35. A n swe r s 657 answers ➔ 7 two points 8 gradient 9 x-intercept 10 zero 11 x = 0 12 Parallel 13 perpendicular 14 Pythagoras’ theorem 15 average Chapter review 1 a b c d –3–2––11 1 2 3 0 –2 –3–2–10 1 2 3 –2 –3–2–10 1 2 3 –2 2 a m = 1 b m = −2 c m = 3 3 a m = 2, b = −3 b m = −1, b = 0 c m = 4, b = −5 4 C 5 a 2 b 6 a y = x + 3 b y = −2x − 2 c y = −x + 5 7 a 3 b y = 2x − 1 c (4, 7) 8 a y b (1, 4) c d 1 (3, 1) 0 x 9 a b c y d 0 x 2y + x = –5 –21–2 –5 10 a b c d 11 D 12 a b 13 a b c y 4y + x – 2.5 = 0 0 x y = x 1 x = 3 0 14 D 15 Answers will vary. 16 C 17 Answers will vary. 18 19 Answers will vary. 20 A 21 (0, −18) 22 x + 2y − 2 = 0 23 2x + 3y − 9 = 0 24 a y = 2x + 8 b y = 2x − 10 25 26 -- 5 -- -- 1 -- 1 -- 27 10 units 28 y = x + 2 29 5x − 2y + 8 = 0 as the gradient is larger 30 (0, 5) and (8, 5). Other answers possible. 31 x = 3. Other answers possible. 32 Distance = units 33 D x −2 −1 0 1 2 y 2 2 2 2 2 x y = x – 2 y 2 3 1 –3 x −2 −1 0 1 2 y 3 4 5 6 7 x y = x + 5 y 5 6 4 2 3 1 –6–5–4–3–2–10 1 x −2 −1 0 1 2 y −10 −6 −2 2 6 x y = 4x – 2 y 2 3 1 –3 x −2 −1 0 1 2 y −4 −1 2 5 8 x y = 3x + 2 y 2 3 1 –3 5 4 -- y = –x + 5 0 x y (1, 1.5) 0 x 5 y = 4x – 2.5 –2.5 2–3 y = x – 1 y –1 3 5–4 y = 3 – x y 3 –2 0 x 4 (4, –2) y = –6x + 25 y 25 0 x 41–6 y y = 20x + 45 0 x –21–4 45 a i − ii iii 4x + 5y − 61 = 0 iv 5x − 4y − 25 = 0 v (9, 5) b Square a i ii (− , 1) iii (4 , 1 ) b Answers will vary. 21–2 5–8 y 0 1 x y = –3x –3 1–4 y 0 4 x y 0 x –2 y = –2 y 0 3 x y 0 3 x y x –3 y x 3 –9 0 y x 3 –2 0 y x 2 0 4 61 4 5 4 1 10 ----- 1 2 2 2 34 ≈ 6 10F 10J
  • 36. 658 A n swe r s answers Chapter 11 — Consumer arithmetic Are you ready? 1 a 24 months b 156 weeks c 21 fortnights d 5 years 2 a $611 b $2619.39 c $27 493.44 d $876.92 3 a $16.98 b $13.63 4 12.25 hours 5 a $12.84 b $32.25 6 a 0.34 b 0.79 c 0.04 d 0.672 e 0.0825 f 0.175 7 a $35 b $356 c $1620 d $571.25 8 a 14% b 65% c 20% Exercise 11A — Wages and salaries 1 a $701.58 b $1403.15 c $3040.17 2 a 813.46 b $1626.92 c $3525 3 a $19 136 b $22 750 c $27 473.68 4 a $20 358 b $21 759.40 c $26 742.56 5 a $9.75 b $12.17 c $11.49 d $10.63 6 a $2390 per month = $28 680 p.a. b $2063.58 per fortnight = $53 653.08 p.a. 7 Paul: $40 508 Hannah: $41 293.15 Hannah, by $785.15 8 $80.78 9 $77.37 10 $148.75 11 Rob (Rhonda gets $342, Rob gets $349.20) 12 $11.25 per hour 13 Gabrielle must work 41 hours to earn more than Russell. 14 a $625 b $1663.50 c $1250 d $8770 15 B 16 Michelle Exercise 11B — Working overtime 1 a $38.43 b $114.12 c $173.25 2 a $512.50 b $675.13 c $842.72 3 a $12.44 b $55.98 c $528.78 4 $542.92 5 a $68.80 b $103.20 c $137.60 d $172.00 6 a $24.80 b $55.80 c $49.60 d $130.20 7 a $21.13 b $126.78 8 Various answers. Check with your teacher. 9 $336 10 B Exercise 11C — Piecework 1 $97.50 2 $89.50 3 $175.50 4 $213.75 5 a $90 b 34 c $13.50 6 a $336 b $503 c $1030 7 a $70 b 3572 c $4.67 8 a $52 b $9.45 9 a $116 b $125 c $132.50 d $16.09 10 D 10 Quick Questions 1 1 $1346.15 2 $29 361.80 3 $368.60 4 $15.95 5 $4666.67 6 38 hours 7 $443.50 8 $538.62 9 $446.25 10 $51.98 Exercise 11D — Commission and royalties 1 $3000 2 a $1280 b $1115.60 3 $1425 4 a $200 b $620 5 a $290 b $482.50 c $641.12 6 a $500 b $590 c $1175 d $1568.75 7 $7200 8 $7450 9 a $1920 b $2020 c $5700 10 a $1600 b $3687.50 c $15 875 11 a Veronica: $276 b $6000 Francis: $216 12 a $725 b $973 c $1078.65 13 A 14 D Exercise 11E — Loadings and bonuses 1 $529.80 2 $410.24 3 $610.85 4 a $638.40 b $446.88 c $3000.48 5 a $592.80 b $2786.16 6 a $574.20 b $100.49 c $589.45 7 a $1022 b $2401.70 8 $744.51 9 $45 918.37 10 a $60 000 b $5000 c 17.9% 11 a $73.50 b $1144.23 c $735.58 d $90 701.81 e 6.7% Exercise 11F — Net earnings 1 a $7.58 b $21.18 c $44.98 d $158.38 e 0 2 a $152.42 b $218.82 c $335.02 d $601.62 e $65.00 3 a $383.37 b $399.97 c $466.22 4 $29 853.25 5 $410.26 6 a i $26.28 ii $243.72 b i $40.73 ii $314.27 c i $11.83 ii $173.17 d i $53.38 ii $356.62 e i $96.88 ii $458.12 7 a $57.88 b 13.6% c $96.58 d $328.42 8 a $525.00 b $87.88 c 16.7% d $320.42 e 61% Exercise 11G — Simple interest 1 a $1200 b $6200 2 $1950 3 a i $100 ii $1100 b i $720 ii $4720 c i $144 ii $944 d i $263.25 ii $2963.25 e i $5048.32 ii $20 726.32
  • 37. A n swe r s 659 answers ➔ 4 a $3300 b $5053.75 5 $849.32 6 a $6162.75 b $205.43 7 $216.00 8 2 years 6 months 9 $1250 10 8.5% 11 a 2 years b 2 years c $600 d $4500 e 8% f 3.8% 12 a $180 000 b $80 550 c $260 550 d $4342.50 13 a i $29.95 ii $3029.25 b i $301.37 ii $25 301.37 10 Quick Questions 2 1 $2580 2 $610 3 $8500 4 $666 666.67 5 $480.98 6 $274.40 7 $5250 8 $4500 9 $6425 10 $63 293.75 Exercise 11H — Compound interest 1 $2317 2 a $21 753.10 b $2753.10 3 a $615 b $649.09 c $6128.31 d $1525.84 e $1346.37 4 a $5900 b Maria’s = $5921.44 c Compounding effect 5 $4836 6 $8840 7 $11 070 8 a $9234 b $12 849.90 c $443.45 d $27 800.61 e $12 667.50 f $124 254 9 D 10 a $20 000 b $23 466.40 c 9.4% p.a. Summary 1 salary 2 overtime 3 commission, Royalties 4 piecework 5 loading 6 bonus 7 gross, net 8 simple interest, principal, decimal, per cent, time period 9 compound 10 (1 + R) 11 initial 12 table Chapter review 1 $1755.77 2 $33 225.92 3 $129.50 4 A 5 $460 6 a $12.34 b $524.28 7 a $27.50 b 80 cards 8 $23.50 9 $570 10 $3428.57 11 a $938.46 b $4410.76 12 $375 000 13 a $490 b $77.38 c 15.8% d $294.77 14 a $147 b $4147 15 $414.06 16 11.5% 17 a $19 009.60 b $3008.60 18 $13 760 19 31.5 20 21 $17.55 22 C Chapter 12 Summary statistics Are you ready? 1 a 40 b 5 2 a 20, 21, 22, 25, 25, 29, 34 b 215, 276, 277, 298, 304, 325, 345, 381, 400 c 0.3, 1.8, 2.8, 2.9, 3.1, 3.5, 3.6, 3.6, 4.6, 5.8, 5.8 3 a 25 b 304 c 3.5 4 a 31 b 133 5 a 7 b 0.5 6 a 2 b 25 c 8 Exercise 12A — Measures of central tendency 1 a 8.4 b 7.7 c 49.7 d 1.7 e 1.8 2 a 2 b 7.8 c 24.9 d 2.3 3 a 7 b 8 c 50 d 1.75 e 1.7 4 a 23 b 116 c 6.28 5 a 5 b 82 c 2.55 6 a 5 b None c 52 d 1.5, 1.7, 1.8 e 1.7 7 a 1 b 7 c 30 d 2.0 8 a 23 b 112 c 6.34 9 a 5 b 81 c 2.4 = 2.6 b 2 c 2 0 1 2 3 4 5 6 d i Median ii Mean iii Mode 11 a $18 000 b $29 444 c $26 000 d i Mode ii Mean 12 75.6 13 7 14 a C b A c D b 141, 139.5, 139.6 c Mean 1 2 -- T I PR = ------- 10 a Score x Frequency f Freq. × score f × x 0 1 0 1 3 3 2 6 12 3 3 9 4 3 12 5 1 5 6 1 6 = 18 Σ(f × x) = 47 15 a Score x Frequency f Freq. × score f × x 137 2 274 138 3 414 139 5 695 140 3 420 141 6 846 142 1 142 = 20 Σ(f × x) = 2791 Σf x Number of people in household Σf 11A 12A
  • 38. 660 A n swe r s answers 16 a The median was calculated by taking the average of the 2 middle scores. b 13 17 2 18 a 55 250 km, 52 000 km, 52 000 km b Discuss in class. c 51 810 km; It is reduced by 3440 km. d 52 000 km e 3333 f 50 000 km; 92% last that distance or more. 10 Quick Questions 1 1 23.6 2 17.5 3 36 4 8.995 5 9.0 6 8.0, 8.6, 9.8, 10.0 8 3.281 25 9 4 10 3 Exercise 12B — Grouped data — mean and modal class 1 a i 63.3 ii 23.1 b i 70–79 ii 30–40 i 27.5 ii 30–39 i 13.6 ii 11–15 i 3.6 ii 3.0–3.9 and 4.0–4.9 i 55.7 ii 60–70 b 61.7 c 60–64, 65–59 d 60–64 e 13; 43 % f 6.7% 7 Score (x) Frequency (f) f × x 1 2 2 2 6 12 3 9 27 4 11 44 5 4 20 Σ f = 32 2 a Class interval Class centre x Frequency f f × x 0–9 4.5 10 45 10–19 14.5 20 290 20–29 24.5 30 735 30–39 34.5 40 1380 40–49 44.5 10 445 50–59 54.5 5 272.5 Σ f = 115 Σ( f × x) = 3167.5 b Class interval Class centre x Frequency f f × x 1–5 3 2 6 6–10 8 9 72 11–15 13 10 130 16–20 18 6 108 21–25 23 4 92 26–30 28 1 28 Σ f = 32 Σ( f × x) = 436 c Class interval Class centre x Frequency f f × x 0–0.9 0.45 1 0.45 1.0–1.9 1.45 2 2.90 2.0–2.9 2.45 4 9.80 3.0–3.9 3.45 10 34.50 4.0–4.9 4.45 10 44.50 5.0–5.9 5.45 3 16.35 Σ f = 30 Σ( f × x) = 108.5 d Class interval Class centre x Frequency f f × x 20–30 25 2 50 30–40 35 5 175 40–50 45 3 135 50–60 55 12 660 60–70 65 18 1170 70–80 75 2 150 Σ f = 42 Σ( f × x) = 2340 3 a Class interval Class centre x Frequency f f × x 45–49 37 2 74 50–54 52 3 156 55–59 57 5 285 60–64 62 7 434 65–69 67 7 469 70–74 72 6 432 Σ f = 30 Σ( f × x) = 1850 4 a Class interval Class centre x Frequency f f × x 0–9 4.5 0 0 10–19 14.5 4 58 20–29 24.5 6 147 30–39 34.5 7 241.5 40–49 44.5 8 356 50–59 54.5 8 436 60–69 64.5 11 709.5 70–79 74.5 8 596 80–89 84.5 7 591.5 90–99 94.5 1 94.5 Σ f = 60 Σ( f × x) = 3230 1 3 --
  • 39. A n swe r s 661 answers ➔ b 53.8 c 16 d 60–69 e 50–59 f 28 1 -- % 3 g 12 10 24.5 44.5 64.5 54.5 5 C 10 Quick Questions 2 1 4.9 2 4 3 4 5 7.9625 6 8 7, 8 84.5 9 23.9 10 21–30 Exercise 12C — Using cumulative frequency to find the median b 8 2 i a b c 22 ii a b c 22 3 a b 24 30 27 24 21 18 15 12 22 20 18 16 14 12 10 8 30 25 20 15 10 5 b Approx. 31 min c 46 d 26 4 Score (x) Frequency (f) f × x 6 12 72 7 16 112 8 25 200 9 17 153 10 10 100 Σ f = 80 Σ( f × x) = 637 Class Class centre (x) Frequency (f) f × x 1–10 5.5 4 22 11–20 15.5 6 93 21–30 25.5 9 229.5 31–40 35.5 2 71 41–50 45.5 4 182 Σ f = 25 Σ( f × x) = 597.5 1 a x f cf 6 4 4 7 3 7 8 6 13 9 2 15 10 5 20 Σ f = 20 Frequency 0 2 4 6 8 4.5 14.5 34.5 Percentages 74.5 94.5 x x f cf 20 3 3 21 5 8 22 9 17 23 7 24 24 6 30 Σ f = 30 x f cf 18 2 2 20 8 10 22 6 16 24 4 20 26 2 22 Σ f = 22 4 a x f cf 10 4 4 20 8 12 30 12 24 40 22 46 50 2 48 60 2 50 Σ f = 50 963 20 21 22 23 24 Cumulative frequency Score 642 18 20 22 24 26 Cumulative frequency Score Cumulative frequency 0 5 15 25 35 45 Time taken (sec) Median = 25 12B 12C
  • 40. 662 A n swe r s answers i 20 16 12 4 8 ii 28 iii 6 i 18 16 14 12 10 2 4 6 8 ii 34.5 iii 4 b 51–60 c 61.3 d 50 45 40 35 30 25 20 15 10 5 e 59.5% f 18 b 30 25 20 15 10 167 174 181 188 c 157 d 154–160 e 9 b 30 25 20 15 10 5 c 22 d 23–27 e 21 9 D Summary 1 mean, median, mode 2 sum, number 3 4middle 5 frequency 6 class centre 7 modal class 8 cumulative frequency 9 ogive Chapter review 1 a Mean = 4.9, median = 5, mode = 5 b Mean = 60.78, median = 62, mode = 45 c Mean = 1.54, median = 1.5, mode = 1.5 5 a Class interval f cf 16–20 4 4 21–25 3 7 26–30 5 12 31–35 5 17 36–40 3 20 S f = 20 b Class interval f cf 8–18 3 3 18–28 2 5 28–38 6 11 38–48 1 12 48–58 2 14 58–68 4 18 S f = 18 6 a Class interval Class centre x Frequency f Cum. frequency cf f × x 41–50 45.5 10 10 455 51–60 55.5 16 26 888 61–70 65.5 13 39 851.5 71–80 75.5 7 46 528.5 81–90 85.5 4 50 342 Σ f = 50 Σ( f × x) = 3065 x Cumulative frequency 0 15 20 25 30 35 40 Cummulative frequency 0 8 18 28 38 48 58 68 x Cummulative frequency 0 40 50 60 70 80 90 Percentage 7 a Class interval Class centre x Frequency f Cum. freq. cf 133–139 136 2 2 140–146 143 3 5 147–153 150 6 11 154–160 157 7 18 161–167 164 6 24 168–174 171 2 26 175–181 178 2 28 182–188 185 2 30 Σ f = 30 8 a Class interval Class centre x Frequency f Cum. freq. cf 8–12 10 3 3 13–17 15 4 7 18–22 20 6 13 23–27 25 8 21 28–32 30 5 26 Σ f = 26 Cumuative frequency 0 5 132 139 146 153 160 Score Cumulative frequency 0 7 12 17 22 27 32 Seedlings per box Σx n ------ Σ f × x , ---------------- Σf