this powerpoint was created for instructional purposes especially in this new normal way of teaching & learning.

2. Good Mor

4. Proportion

5. PROPORTIONS
d
c
b
a

4
6
2
3

What is a
proportion?
A proportion is an
equation that equates two
ratios
The ratio of dogs and cats was 3/2
The ratio of dogs and cats now is
6/4=3/2
So we have a proportion :

6. PROPERTIES OF A
PROPORTION?
4
6
2
3

2x6=12 3x4 = 12
3x4 =
2x6
Cross Product
Property

7. PROPERTIES OF A
PROPORTION?
d
c
b
a

1.Cross Product
Property
ad =
bc
means
extrem
es

8. PROPERTIES OF A
PROPORTION?
4
6
2
3

6
4
3
2

If
The
n
2. Reciprocal
Property

9. 6
2
7 x

Solve for x
7(6) = 2x
42 = 2x
21 = x
Cross Product Property
1. Example of Cross Product Property

10. 2.
EXAMPLE?
x
12
2
7

7
24
Solve for
x
7x = 2(12)
7x = 24
x =
2. Cross Product
Property
Can you solve it
using Reciprocal
Property? If yes,
would it be easier?

11. TRY
THESE
4
3

x
x
3
1
7


Solve for
x
7x = (x-1)3
7x = 3x – 3
4x = -3
x =
Cross Product Property
Again, Reciprocal
Property?

12. gal
x
miles
gal
miles
_
)
5
5
(
1
30 

x
10
1
30

If your car gets 30 miles/gallon, how many gallons of gas
do you need to commute to school everyday?
5 miles to
school
5 miles to
home
Let x be the number gallons we need for a day
Can you solve it
from here?
x = 1
3 Gal
TRY THESE

13. So you use up 1/3 gallon a day. How many gallons would you
use for a week?
5 miles to school
5 miles to home
Let t be the number of gallons we need for a week
days
gal
t
day
gal
5
_
1
3
/
1

5
1
3
/
1 t

5
3
1 t
 t
3
)
5
(
1 
3
5

t Gal
What property is this?

14. So you use up 5/3 gallons a week (which is about 1.67
gallons). Consider if the price of gas is Php3.69 /gal, how
much would it cost for a week?
Let s be the sum of cost for a week
5 miles to school
5 miles to home
3.69(1.67) = 1s s = Php 6.16
Php 3.69 = s- Php
1gallon 1.67gallons
3.69= S
1 1.67

15. Keep in
Mind
A proportion is an equation
that equates two ratios
1.Cross Product Property
2. Reciprocal Property
ad = bc
4
6
2
3

6
4
3
2
