ALGEBRA
BY ADJEKUKOR, CYNTHIA UFUOMA
1
CONTENTS
Algebra 1
Algebra 2
Algebra 3
Algebra 4
Algebra 5
Algebra 6
2
ALGEBRA 1
3
Contents
Introduction
Solution to Puzzle
Definition of terms
Rules in Algebra
Collecting Like Terms
Similar Terms
4
INTRODUCTION
 Algebra is that aspect of mathematics that involves the use
of numbers and letters or letters only.
 Puzzle
 Think of a number
 Add 15 to it
 Double the result
 Add this to the number you first thought of
 Divide the result by 3
 Take away the number you first thought of
 The answer is 10 Why?
5
SOLUTION TO PUZZLE
Let letter ‘a’ be the number
(a + 15) × 2 = 2a + 30
2a + 30 + a = 3a + 30
(3a + 30) ⁄ 3 = 3a ⁄ 3 + 30 / 3
3a ⁄ 3 + 30 / 3 = a + 10
a + 10 − a = 10
6
DEFINITION OF TERMS
Constant: the letter ‘a’ used in the puzzle is a constant.
Variable: 2 + 3 = 3 + 2 Thus a + b = b + a.
Now ‘a’ and ‘b’ are variables because they represent any
two numbers.
Coefficient and Term: 5 × y = 5y. Now number ‘5’ which
is attached to letter ‘y’ is seen as the coefficient of y.
While y is the term.
7
RULES IN ALGEBRA
There are similar to the rules in arithmetic.
Commutativity: two numbers ‘a’ and ‘b’ can
be added or multiplied in any other without
affecting the results.
a + b = b + a & a × b = b × a
But a − b ≠ b − a unless a = b
 & a ⁄ b ≠ b ⁄ a unless b = a and neither equals zero.
8
Rules in Algebra
Associativity: The way in which the numbers a , b and c
are associated under addition or multiplication does
not affect the result.
 a + (b + c) = (a + b) + c = a + b + c
a × (b × c) = (a × b) × c = a × b × c
But for division and multiplication
x − (y − z) ≠ (x−y) − z unless z = 0
And x ÷ (y ÷ z) ≠ (x ÷ y) ÷ z unless z = 1 and y ≠ 0
9
Rules in Algebra
Distributivity: this states that multiplication are
distributed over addition and subtraction from both
left to right.
• For example:
x (y + z) = xy + xz (distributed from the left)
(x + y)z = xz + yz (distributed from the right)
x(y − z) = xy − xz (distributed from the left)
(x − y)z = xz − xy (distributed from the right)
• But division is distributed only over addition and
subtraction from the right and not from the left.
10
COLLECTING LIKE TERMS
 Terms which have the same variable are called like terms.
 And they can be collected together by addition or
subtraction.
 For example
 4x + 3y − 2z + 5y − 3x + 4z
 First, collect like terms and rearrange the operation.
 4x − 3x + 3y + 5y − 2z + 4z
 With these, you can simplify
 x + 8y + 2z
11
Collecting Like Terms
Simplify 4uv − 7uz − 6wz + 2uv + 3wz
Collect like terms.
Note the terms here are double letter and
include: uv, uz and wz.
4uv + 2uv − 7uz − 6wz + 3wz
6uv − 7uz −3wz
12
SIMILAR TERMS
Factorize
ab + bc
First question, what term is similar between ab
and bc? It is b. So bring out b to stand alone.
b (a + c)
In expanding the bracket, you will have b × a = ab
+ b × c = bc.
13
Similar Terms
Factorize 3pq − 3qr.
Bring out what is similar to stand alone.
3q (p − r)
Factorise 9st − 3sv − 6sw
3s (3t − v − 2w)
14
ALGEBRA 2
15
Contents
Expanding the Brackets
Nested Brackets
Multiplication of Algebraic Expressions
of a Single Variable
Division of One Expression by another
16
EXPANDING BRACKETS
In expanding brackets, you multiply each of the terms
enclosed in brackets by the term outside the bracket.
But if the term outside the bracket has a negative sign,
the signs of the terms enclosed in the bracket will
change.
3x (y − 2z)
(3x × y) − (3x × 2z)
3xy − 6xz
17
Expanding Brackets
What if you have a negative sign?
− 2y (2x − 4z)
First multiply through by 2y
− [ (2y × 2x) − (2y × 4z)]
− [4xy − 8yz]
Multiply through by the negative sign
−4xy + 8yz
18
NESTED BRACKETS
 When ever an algebraic expression contains brackets that
are nested within each other, you will start simplifying from
the innermost bracket.
 4 {2a + 3 [5 −2 (a−b)]}
 Start simplifying from innermost bracket
 4 {2a + 3[5 − 2a − 2b]}
 Next bracket
 4{2a + 15 − 6a − 6b}
 Next bracket
 8a + 60 − 24a − 24b
19
Nested Brackets
Collect like terms
8a − 24a + 60 − 24b
Simplify
−16a + 60 −24b
Rearrange
−16a −24b + 60
20
Nested Brackets
Simplify
8x (y − z) + 2y (7x + z)
Expand the bracket
(8xy − 8xz) + (14xy + 2yz)
Multiply the second bracket through by +
8xy − 8xz + 14xy + 2yz
21
Nested Brackets
Collect like terms
8xy + 14xy − 8xz + 2yz
Simplify
22xy − 8xz + 2yz
Factorise
2 (11xy − 4xz + yz)
It can still be factorised further
2[ x (11y − 4z) + yz}
22
Nested Brackets
(3a − b) (b − 3a) + b2
Expand the brackets
3a (b − 3a) −b (b − 3a) + b2
3ab − 9a2 − b2 + 3ab + b2
Collect like terms
3ab + 3ab − 9a2 − b2 + b2
6ab − 9a2
Factorise
3a (2b − 3a)
23
MULTIPLICATION OF ALGEBRAIC
EXPRESSIONS OF A SINGLE VARIABLE
 (x + 2) (x + 3)
Multiply (x + 3) by x and (x + 3) by +2
x (x + 3) +2 (x + 3)
x2 + 3x + 2x + 6
Simplify
x2 + 5x + 6
24
Multiplication of Algebraic Expressions
of a Single Variable
(2x + 5) (x2 + 3x + 4)
Multiply (x2 + 3x + 4) by 2x and (x2 + 3x + 4) by +5
2x (x2 + 3x + 4) +5 (x2 + 3x + 4)
Expand the bracket
2x3 + 6x2 + 8x + 5x2 + 15x + 20
Collect like terms
2x3 + 6x2 + 5x2 + 8x + 15x + 20
Simplify
2x3 + 11x2 + 23x + 20
25
DIVISION OF ONE EXPRESSION BY
ANOTHER
 (12x3 − 2x2 − 3x + 28) ÷ 3x + 4
 So, we are going to do long division
 3x+4 √ (12x3 − 2x2 − 3x + 28)
 We will only divide the first term of the numerator (12x3) by 3x. Thus
4x2. Then multiply 3x+4 by 4x2. it will give you 12x3 + 16x.
 3x+4 √ (12x3 − 2x2 − 3x + 28)
 −(12x3 + 16x2)
 The result will be −18x2 − 3x + 28
 Then we will continue to divide the first term of every results by 3x.
And then multiply 3x+4 by the result. Then do the normal operation
until there is nothing to divide.
 Therefore (12x3 − 2x2 − 3x + 28) ÷ 3x + 4 is 4x2 − 6x +7
26
ALGEBRA 3
ALGEBRAIC FRACTIONS
27
Contents
Addition and Subtraction of
Algebraic Fractions
Multiplication and Division of
Algebraic Fractions
28
ADDITION AND SUBTRACTION OF
ALGEBRAIC FRACTIONS
Simplify
 a⁄b − c⁄d2 + d⁄a
First, look for the LCM
The LCM is abd2
Divide the LCM (the new denominator) by the other
denominators (b, d2, & a).
Then multiply each of your results by the
corresponding numerator of the denominators.
(a2d2 − abc + bd3) / abd2
29
Addition and Subtraction of Algebraic
Fractions
 Simplify 2/(x+1) + 4/(x+2)
 First, look for the LCM which is (x+1) (x+2)
 Divide the LCM by the denominator (x+1). The answer is (x+2). Then (x+2)
multiplied by 2 is 2(x+2).
 For the second one divide the LCM by the denominator. The answer is (x+1).
Then (x+1) multiplied by 4 is 4(x+1).
 Add your two results together and divide by the denominator
 [2(x+2) + 4(x+1)] / (x+1) (x+2)
 Expand the brackets of the numerator and denominator
 (2x + 4 + 4x +4) / ( x2 +3x +2)
 Collect like terms at the numerator
 (2x + 4x + 4 + 4) / ( x2 +3x +2)
 (6x + 8 )/ (x2 +3x +2)
30
MULTIPLICATION AND DIVISION
 (a/b) × (c/d) = (ac) / (bd)
 (a/b) ÷ (c/d) = (a/b) × (d/c) = (ad) / (bc)
 Simplify (2a / 3b) ÷ (a2b / 6)
 Remember the switch in division
 (2a/3b) × (6/a2b)
 (2a × 6) / (3b × a2b)
 (12a) / (3a2b2)
 Note 3a can divide both the numerator and denominator. 12a / 3a =
4 and 3a2b2 divided by 3a is ab2
 Therefore, your answer will be 4 / ab2
31
ALGEBRA 4
32
Contents
Factorisation of Algebraic Expression
Useful Products of Two Simple
Factors
Examples
33
FACTORISATION OF ALGEBRAIC
EXPRESSION
Common factors
• Factorize 8x4y3 + 6x3y2
This can be written as
8xxxxyyy + 6xxxyy
 what is common?
2xxxyy (4xy +3)
This can be written as
2x3y2 (4xy +3)
34
Factorisation of Algebraic Expression
Common factors by grouping
• Factorize 2ac + 6bc + ad +3bd
Group the expression in two brackets
(2ac + 6bc) + (ad +3bd)
What is common in each bracket?
2c(a+3b) +d (a+3b)
They re two (a+3b), so you pick one and select the outer
terms as a group.
(2c+d) (a+3b)
35
USEFUL PRODUCTS OF TWO SIMPLE
FACTORS
(a+b) (a−b)
(a+b)2 = (a+b) (a+b) = a(a+b) + b(a+b)
• a2 + ab + ab + b2 = a2 +2ab + b2
(a−b)2 = (a−b) (a−b) = a(a−b) − b(a−b)
• a2 −ab −ab + b2 = a2 −2ab + b2
(a−b) (a+b) = a(a+b) − b(a+b)
• a2 + ab −ab − b2 = a2 − b2
36
Useful Products of Two Simple Factors
Remember that
(a+b)2 = a2 + 2ab +b2
(a−b)2 = a2 − 2ab +b2
(a+b) (a−b) = a2 − b2 Difference of two squares
37
EXAMPLES
 Factorize 4a2 − 12a + 9
 Present this as
 22a2 − 12a + 32
 which is
 (2a)2 − 12a + 32
 This can be represented to look like this
 a2 − 2ab +b2
 Note a = 2a and b = 3 and 2ab= 2(2a)(3)
 Therefore (2a)2 − 12a + 32 can be written as
 (2a)2 − 2(2a)(3) + 32
 Recall again (a−b)2 = a2 − 2ab +b2 and a = 2a while b=3.
 Thus (2a)2 − 2(2a)(3) + 32 = (2a−3)2
 That is 4a2 − 12a + 9 = (2a−3)2
38
Examples
Factorize 16x2 + 40xy + 25y2
This can be written as
42x2 + 40xy + 52y2
Which is (4x)2 + 40xy + (5y)2
This looks like a2 + 2ab +b2 where a= 4x b =5y then 2ab =
2(4x)(5y)
Thus (4x)2 + 40xy + (5y)2 can be written as
(4x)2 + 2(4x)(5y) + (5y)2
Recall again that (a+b)2 = a2 + 2ab + b2
Thus (4x)2 + 2(4x)(5y) + (5y)2 = (4x + 5y)2
39
Examples
Factorise 9a2 − 16x2
This can be written as
32a2 − 42x2 which can also be written as
(3a)2 − (4x)2 that is similar to a2 − b2 where a= 3a and
b= 4x
Recall (a+b) (a−b) = a2 − b2
Therefore (3a)2 − (4x)2 = (3a + 4x) (3a − 4x)
Thus 9a2 − 16x2 = (3a + 4x) (3a − 4x)
40
ALGEBRA 5
TRINOMIAL EXPRESSION
41
Contents
Trinomial Expression
Quadratic Expression as the Product of
Two Simple Factors
Factorisation of Quadratic Expression ax2
+ bx +c When a = 1
42
TRINOMIAL EXPRESSION
These types of expression are always in three
terms
They are mostly quadratic equation.
They take the form ax2 + bx + c
43
QUADRATIC EXPRESSION AS THE
PRODUCT OF TWO SIMPLE FACTORS
(x+g) (x+k) = x (x+k) + g (x+k)
x2 + kx + gx + gk
x2 + (k+g)x + gk
The coefficient of the middle term (k+g)x sum
of the constant g and k and the last term is the
product of the constants g and k.
44
Quadratic Expression as the Product of
Two Simple Factors
(x−g) (x−k) = x (x−k) − g (x−k)
x2 −kx − gx + gk
x2 −(k+g)x +gk
The coefficient of the middle term is minus the
sum of the two constants g and k while the last
term is the product of the two constants g and k
45
Quadratic Expression as the Product of
Two Simple Factors
(x+g) (x−k) = x (x−k) + g (x−k)
x2 −kx + gx − gk
 x2 + (g−k)x − gk
The coefficient of the middle term is the
difference of the two constants g and k while
the last term is minus the product of the two
constants g and k.
46
FACTORISATION OF QUADRATIC
EXPRESSION ax2 + bx +c WHEN a = 1
(x + f1) and (x + f2) are the factors of the quadratic
expression.
If c is positive
f1 and f2 are factors of c and bx + c have a sign of b. then
the sum of f1 and f2 is b.
If c is negative
f1 and f2 are factors of c and have opposite signs. Then the
numerical larger one have the sign of b and the difference
between f1 and f2 is b.
47
Factorisation of Quadratic Expression
ax2 + bx +c When a = 1
 Factorize x2 + 5x + 6
 Note C is positive. So therefore f1 and f2 are factors of c. what
are the factors of 6?
 1 and 6
 2 and 3
 The factors have the sign of b which is +. And the sum of f1 and
f2 is b.
 So 1+6 = 7 ≠ b but 2+3 = 5 = b
 the factors of the quadratic expression will be (x + f1) and (x + f2)
 Which is (x+2) and (x+3)
 That is x2 + 5x + 6 = (x+2) and (x+3)
48
Factorisation of Quadratic Expression
ax2 + bx +c When a = 1
 Factorize x2 − 9x + 20
 Note C is positive. So therefore f1 and f2 are factors of c. what are the
factors of 20?
 1 and 20
 2 and 10
 4 and 5
 The factors have the sign of b which is −. And the sum of f1 and f2 is b.
 −1 −20 = −21≠b , −2 −10 =−12≠b and −4−5 = −9=b
 the factors of the quadratic expression will be (x + f1) and (x + f2)
 Which is (x−4) and (x−5)
 That is x2 −9x +20 = (x−4) and (x−5)
49
Factorisation of Quadratic Expression
ax2 + bx +c When a = 1
Factorize x2 − 2x −35
f1 and f2 are factors of c and have opposite signs. Then the
numerical larger one have the sign of b and the difference
between f1 and f2 is b.
The factors of 35 are
1 and 35, 5 and 7
The numerical larger one which is 7 have the sign of b that
is the negative sign thus 5 has the positive sign.
Then −7 + 5 = −2 = b
Thus x2 − 2x −35 = (x + 5) (x−7)
50
Algebra 6
51
Contents
Factorisation of Quadratic Expression ax2
+ bx +c When a ≠ 1
Test for Simple Factors
52
FACTORISATION OF QUADRATIC
EXPRESSION ax2 + bx +c WHEN a ≠ 1
Obtain /ac/
If C is positive, we will select two factors of /ac/ whose
sum is equal to /b/. Both of these factors will carry the sign
of b.
If C is negative, we will select two factors of /ac/ which
differ by the values of /b/. The numerically larger one will
have the sign of b. the two factors will thus possess
opposite signs.
 then ax2 + bx +c will now be written as
 ax2 + f1x + f2x +c
 you will now factorise by grouping.
53
Factorisation of Quadratic Expression
ax2 + bx +c When a ≠ 1
 Factorise 6x2 + 11x + 3
 ax2 + bx +c
 a = 6, b = 11, c = 3
 Now /ac/ = /6 × 3/ = /18/ =18
 Since c is positive, we are interested in .two factors of /ac/ whose sum is equal
to /b/. And the two factors are 2 and 9.
 So therefore ax2 + bx +c will now be written as
 ax2 + f1x + f2x +c
 6x2 + 2x + 9x + 3
 Factorise by grouping
 (6x2 + 2x) + (9x + 3)
 2x (3x + 1) +3 (3x +1)
 (2x +3) (3x+1)
54
Factorisation of Quadratic Expression
ax2 + bx +c When a ≠ 1
 Factorise 8x2 + 18x −5
 ax2 + bx +c
 a = 8, b = 18, c = −5
 Now /ac/ = /8 × −5 / = /−40/ = 40
 Since C is negative, we will select two factors of /ac/ which differ by the values of /b/.
The numerically larger one will have the sign of b. And the two factors are + 20 and −2
 So therefore ax2 + bx +c will now be written as
 ax2 + f1x + f2x +c
 8x2 −2x +20x −5
 Factorise by grouping
 (8x2 −2x) +(20x −5)
 2x(4x − 1) +5 (4x − 1)
 (2x+5) (4x − 1)
55
TEST FOR SIMPLE FACTORS
Some quadratic equations are not capable of
being written as the product of simple factors.
i.e. factors where all the coefficients are integers.
To determine whether ax2 + bx +c can be
factorised into two simple factors.
We will first evaluate the expression (b2 −4ac).
56
Test for Simple Factors
If b2 −4ac is a perfect square; can be written as k2.
then ax2 + bx +c can be factorised into simple
factors.
But if b2 −4ac is not a perfect square; cannot be
written as k2.
then ax2 + bx +c cannot be factorised into simple
factors
57
Test for Simple Factors
Test for the simple factors of 3x2 − 4x +5 .
a=3 b = −4 c=5
Using b2 −4ac , we will have (−4)2 − 4 (3) (5)
(−4)2 − 4 × 3 × 5
16 − 60
−44
Note −44 is not a perfect square, thus the expression
3x2 − 4x +5 have no simple factors.
58
Test for Simple Factors
 Test for the simple factors of 2x2 +5x −3 .
 a=2 b = 5 c=−3
 Using b2 −4ac , we will have (5)2 − 4 (2) (−3)
 (5)2 − 4 × 2 × −3
 25 − 4(−6)
 25 + 24
 49
 Note 49 is a perfect square; can be written as 72.
 thus the expression 2x2 + 5x −3 can be factorised into simple
factors
59
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61

Algebra

  • 1.
  • 2.
    CONTENTS Algebra 1 Algebra 2 Algebra3 Algebra 4 Algebra 5 Algebra 6 2
  • 3.
  • 4.
    Contents Introduction Solution to Puzzle Definitionof terms Rules in Algebra Collecting Like Terms Similar Terms 4
  • 5.
    INTRODUCTION  Algebra isthat aspect of mathematics that involves the use of numbers and letters or letters only.  Puzzle  Think of a number  Add 15 to it  Double the result  Add this to the number you first thought of  Divide the result by 3  Take away the number you first thought of  The answer is 10 Why? 5
  • 6.
    SOLUTION TO PUZZLE Letletter ‘a’ be the number (a + 15) × 2 = 2a + 30 2a + 30 + a = 3a + 30 (3a + 30) ⁄ 3 = 3a ⁄ 3 + 30 / 3 3a ⁄ 3 + 30 / 3 = a + 10 a + 10 − a = 10 6
  • 7.
    DEFINITION OF TERMS Constant:the letter ‘a’ used in the puzzle is a constant. Variable: 2 + 3 = 3 + 2 Thus a + b = b + a. Now ‘a’ and ‘b’ are variables because they represent any two numbers. Coefficient and Term: 5 × y = 5y. Now number ‘5’ which is attached to letter ‘y’ is seen as the coefficient of y. While y is the term. 7
  • 8.
    RULES IN ALGEBRA Thereare similar to the rules in arithmetic. Commutativity: two numbers ‘a’ and ‘b’ can be added or multiplied in any other without affecting the results. a + b = b + a & a × b = b × a But a − b ≠ b − a unless a = b  & a ⁄ b ≠ b ⁄ a unless b = a and neither equals zero. 8
  • 9.
    Rules in Algebra Associativity:The way in which the numbers a , b and c are associated under addition or multiplication does not affect the result.  a + (b + c) = (a + b) + c = a + b + c a × (b × c) = (a × b) × c = a × b × c But for division and multiplication x − (y − z) ≠ (x−y) − z unless z = 0 And x ÷ (y ÷ z) ≠ (x ÷ y) ÷ z unless z = 1 and y ≠ 0 9
  • 10.
    Rules in Algebra Distributivity:this states that multiplication are distributed over addition and subtraction from both left to right. • For example: x (y + z) = xy + xz (distributed from the left) (x + y)z = xz + yz (distributed from the right) x(y − z) = xy − xz (distributed from the left) (x − y)z = xz − xy (distributed from the right) • But division is distributed only over addition and subtraction from the right and not from the left. 10
  • 11.
    COLLECTING LIKE TERMS Terms which have the same variable are called like terms.  And they can be collected together by addition or subtraction.  For example  4x + 3y − 2z + 5y − 3x + 4z  First, collect like terms and rearrange the operation.  4x − 3x + 3y + 5y − 2z + 4z  With these, you can simplify  x + 8y + 2z 11
  • 12.
    Collecting Like Terms Simplify4uv − 7uz − 6wz + 2uv + 3wz Collect like terms. Note the terms here are double letter and include: uv, uz and wz. 4uv + 2uv − 7uz − 6wz + 3wz 6uv − 7uz −3wz 12
  • 13.
    SIMILAR TERMS Factorize ab +bc First question, what term is similar between ab and bc? It is b. So bring out b to stand alone. b (a + c) In expanding the bracket, you will have b × a = ab + b × c = bc. 13
  • 14.
    Similar Terms Factorize 3pq− 3qr. Bring out what is similar to stand alone. 3q (p − r) Factorise 9st − 3sv − 6sw 3s (3t − v − 2w) 14
  • 15.
  • 16.
    Contents Expanding the Brackets NestedBrackets Multiplication of Algebraic Expressions of a Single Variable Division of One Expression by another 16
  • 17.
    EXPANDING BRACKETS In expandingbrackets, you multiply each of the terms enclosed in brackets by the term outside the bracket. But if the term outside the bracket has a negative sign, the signs of the terms enclosed in the bracket will change. 3x (y − 2z) (3x × y) − (3x × 2z) 3xy − 6xz 17
  • 18.
    Expanding Brackets What ifyou have a negative sign? − 2y (2x − 4z) First multiply through by 2y − [ (2y × 2x) − (2y × 4z)] − [4xy − 8yz] Multiply through by the negative sign −4xy + 8yz 18
  • 19.
    NESTED BRACKETS  Whenever an algebraic expression contains brackets that are nested within each other, you will start simplifying from the innermost bracket.  4 {2a + 3 [5 −2 (a−b)]}  Start simplifying from innermost bracket  4 {2a + 3[5 − 2a − 2b]}  Next bracket  4{2a + 15 − 6a − 6b}  Next bracket  8a + 60 − 24a − 24b 19
  • 20.
    Nested Brackets Collect liketerms 8a − 24a + 60 − 24b Simplify −16a + 60 −24b Rearrange −16a −24b + 60 20
  • 21.
    Nested Brackets Simplify 8x (y− z) + 2y (7x + z) Expand the bracket (8xy − 8xz) + (14xy + 2yz) Multiply the second bracket through by + 8xy − 8xz + 14xy + 2yz 21
  • 22.
    Nested Brackets Collect liketerms 8xy + 14xy − 8xz + 2yz Simplify 22xy − 8xz + 2yz Factorise 2 (11xy − 4xz + yz) It can still be factorised further 2[ x (11y − 4z) + yz} 22
  • 23.
    Nested Brackets (3a −b) (b − 3a) + b2 Expand the brackets 3a (b − 3a) −b (b − 3a) + b2 3ab − 9a2 − b2 + 3ab + b2 Collect like terms 3ab + 3ab − 9a2 − b2 + b2 6ab − 9a2 Factorise 3a (2b − 3a) 23
  • 24.
    MULTIPLICATION OF ALGEBRAIC EXPRESSIONSOF A SINGLE VARIABLE  (x + 2) (x + 3) Multiply (x + 3) by x and (x + 3) by +2 x (x + 3) +2 (x + 3) x2 + 3x + 2x + 6 Simplify x2 + 5x + 6 24
  • 25.
    Multiplication of AlgebraicExpressions of a Single Variable (2x + 5) (x2 + 3x + 4) Multiply (x2 + 3x + 4) by 2x and (x2 + 3x + 4) by +5 2x (x2 + 3x + 4) +5 (x2 + 3x + 4) Expand the bracket 2x3 + 6x2 + 8x + 5x2 + 15x + 20 Collect like terms 2x3 + 6x2 + 5x2 + 8x + 15x + 20 Simplify 2x3 + 11x2 + 23x + 20 25
  • 26.
    DIVISION OF ONEEXPRESSION BY ANOTHER  (12x3 − 2x2 − 3x + 28) ÷ 3x + 4  So, we are going to do long division  3x+4 √ (12x3 − 2x2 − 3x + 28)  We will only divide the first term of the numerator (12x3) by 3x. Thus 4x2. Then multiply 3x+4 by 4x2. it will give you 12x3 + 16x.  3x+4 √ (12x3 − 2x2 − 3x + 28)  −(12x3 + 16x2)  The result will be −18x2 − 3x + 28  Then we will continue to divide the first term of every results by 3x. And then multiply 3x+4 by the result. Then do the normal operation until there is nothing to divide.  Therefore (12x3 − 2x2 − 3x + 28) ÷ 3x + 4 is 4x2 − 6x +7 26
  • 27.
  • 28.
    Contents Addition and Subtractionof Algebraic Fractions Multiplication and Division of Algebraic Fractions 28
  • 29.
    ADDITION AND SUBTRACTIONOF ALGEBRAIC FRACTIONS Simplify  a⁄b − c⁄d2 + d⁄a First, look for the LCM The LCM is abd2 Divide the LCM (the new denominator) by the other denominators (b, d2, & a). Then multiply each of your results by the corresponding numerator of the denominators. (a2d2 − abc + bd3) / abd2 29
  • 30.
    Addition and Subtractionof Algebraic Fractions  Simplify 2/(x+1) + 4/(x+2)  First, look for the LCM which is (x+1) (x+2)  Divide the LCM by the denominator (x+1). The answer is (x+2). Then (x+2) multiplied by 2 is 2(x+2).  For the second one divide the LCM by the denominator. The answer is (x+1). Then (x+1) multiplied by 4 is 4(x+1).  Add your two results together and divide by the denominator  [2(x+2) + 4(x+1)] / (x+1) (x+2)  Expand the brackets of the numerator and denominator  (2x + 4 + 4x +4) / ( x2 +3x +2)  Collect like terms at the numerator  (2x + 4x + 4 + 4) / ( x2 +3x +2)  (6x + 8 )/ (x2 +3x +2) 30
  • 31.
    MULTIPLICATION AND DIVISION (a/b) × (c/d) = (ac) / (bd)  (a/b) ÷ (c/d) = (a/b) × (d/c) = (ad) / (bc)  Simplify (2a / 3b) ÷ (a2b / 6)  Remember the switch in division  (2a/3b) × (6/a2b)  (2a × 6) / (3b × a2b)  (12a) / (3a2b2)  Note 3a can divide both the numerator and denominator. 12a / 3a = 4 and 3a2b2 divided by 3a is ab2  Therefore, your answer will be 4 / ab2 31
  • 32.
  • 33.
    Contents Factorisation of AlgebraicExpression Useful Products of Two Simple Factors Examples 33
  • 34.
    FACTORISATION OF ALGEBRAIC EXPRESSION Commonfactors • Factorize 8x4y3 + 6x3y2 This can be written as 8xxxxyyy + 6xxxyy  what is common? 2xxxyy (4xy +3) This can be written as 2x3y2 (4xy +3) 34
  • 35.
    Factorisation of AlgebraicExpression Common factors by grouping • Factorize 2ac + 6bc + ad +3bd Group the expression in two brackets (2ac + 6bc) + (ad +3bd) What is common in each bracket? 2c(a+3b) +d (a+3b) They re two (a+3b), so you pick one and select the outer terms as a group. (2c+d) (a+3b) 35
  • 36.
    USEFUL PRODUCTS OFTWO SIMPLE FACTORS (a+b) (a−b) (a+b)2 = (a+b) (a+b) = a(a+b) + b(a+b) • a2 + ab + ab + b2 = a2 +2ab + b2 (a−b)2 = (a−b) (a−b) = a(a−b) − b(a−b) • a2 −ab −ab + b2 = a2 −2ab + b2 (a−b) (a+b) = a(a+b) − b(a+b) • a2 + ab −ab − b2 = a2 − b2 36
  • 37.
    Useful Products ofTwo Simple Factors Remember that (a+b)2 = a2 + 2ab +b2 (a−b)2 = a2 − 2ab +b2 (a+b) (a−b) = a2 − b2 Difference of two squares 37
  • 38.
    EXAMPLES  Factorize 4a2− 12a + 9  Present this as  22a2 − 12a + 32  which is  (2a)2 − 12a + 32  This can be represented to look like this  a2 − 2ab +b2  Note a = 2a and b = 3 and 2ab= 2(2a)(3)  Therefore (2a)2 − 12a + 32 can be written as  (2a)2 − 2(2a)(3) + 32  Recall again (a−b)2 = a2 − 2ab +b2 and a = 2a while b=3.  Thus (2a)2 − 2(2a)(3) + 32 = (2a−3)2  That is 4a2 − 12a + 9 = (2a−3)2 38
  • 39.
    Examples Factorize 16x2 +40xy + 25y2 This can be written as 42x2 + 40xy + 52y2 Which is (4x)2 + 40xy + (5y)2 This looks like a2 + 2ab +b2 where a= 4x b =5y then 2ab = 2(4x)(5y) Thus (4x)2 + 40xy + (5y)2 can be written as (4x)2 + 2(4x)(5y) + (5y)2 Recall again that (a+b)2 = a2 + 2ab + b2 Thus (4x)2 + 2(4x)(5y) + (5y)2 = (4x + 5y)2 39
  • 40.
    Examples Factorise 9a2 −16x2 This can be written as 32a2 − 42x2 which can also be written as (3a)2 − (4x)2 that is similar to a2 − b2 where a= 3a and b= 4x Recall (a+b) (a−b) = a2 − b2 Therefore (3a)2 − (4x)2 = (3a + 4x) (3a − 4x) Thus 9a2 − 16x2 = (3a + 4x) (3a − 4x) 40
  • 41.
  • 42.
    Contents Trinomial Expression Quadratic Expressionas the Product of Two Simple Factors Factorisation of Quadratic Expression ax2 + bx +c When a = 1 42
  • 43.
    TRINOMIAL EXPRESSION These typesof expression are always in three terms They are mostly quadratic equation. They take the form ax2 + bx + c 43
  • 44.
    QUADRATIC EXPRESSION ASTHE PRODUCT OF TWO SIMPLE FACTORS (x+g) (x+k) = x (x+k) + g (x+k) x2 + kx + gx + gk x2 + (k+g)x + gk The coefficient of the middle term (k+g)x sum of the constant g and k and the last term is the product of the constants g and k. 44
  • 45.
    Quadratic Expression asthe Product of Two Simple Factors (x−g) (x−k) = x (x−k) − g (x−k) x2 −kx − gx + gk x2 −(k+g)x +gk The coefficient of the middle term is minus the sum of the two constants g and k while the last term is the product of the two constants g and k 45
  • 46.
    Quadratic Expression asthe Product of Two Simple Factors (x+g) (x−k) = x (x−k) + g (x−k) x2 −kx + gx − gk  x2 + (g−k)x − gk The coefficient of the middle term is the difference of the two constants g and k while the last term is minus the product of the two constants g and k. 46
  • 47.
    FACTORISATION OF QUADRATIC EXPRESSIONax2 + bx +c WHEN a = 1 (x + f1) and (x + f2) are the factors of the quadratic expression. If c is positive f1 and f2 are factors of c and bx + c have a sign of b. then the sum of f1 and f2 is b. If c is negative f1 and f2 are factors of c and have opposite signs. Then the numerical larger one have the sign of b and the difference between f1 and f2 is b. 47
  • 48.
    Factorisation of QuadraticExpression ax2 + bx +c When a = 1  Factorize x2 + 5x + 6  Note C is positive. So therefore f1 and f2 are factors of c. what are the factors of 6?  1 and 6  2 and 3  The factors have the sign of b which is +. And the sum of f1 and f2 is b.  So 1+6 = 7 ≠ b but 2+3 = 5 = b  the factors of the quadratic expression will be (x + f1) and (x + f2)  Which is (x+2) and (x+3)  That is x2 + 5x + 6 = (x+2) and (x+3) 48
  • 49.
    Factorisation of QuadraticExpression ax2 + bx +c When a = 1  Factorize x2 − 9x + 20  Note C is positive. So therefore f1 and f2 are factors of c. what are the factors of 20?  1 and 20  2 and 10  4 and 5  The factors have the sign of b which is −. And the sum of f1 and f2 is b.  −1 −20 = −21≠b , −2 −10 =−12≠b and −4−5 = −9=b  the factors of the quadratic expression will be (x + f1) and (x + f2)  Which is (x−4) and (x−5)  That is x2 −9x +20 = (x−4) and (x−5) 49
  • 50.
    Factorisation of QuadraticExpression ax2 + bx +c When a = 1 Factorize x2 − 2x −35 f1 and f2 are factors of c and have opposite signs. Then the numerical larger one have the sign of b and the difference between f1 and f2 is b. The factors of 35 are 1 and 35, 5 and 7 The numerical larger one which is 7 have the sign of b that is the negative sign thus 5 has the positive sign. Then −7 + 5 = −2 = b Thus x2 − 2x −35 = (x + 5) (x−7) 50
  • 51.
  • 52.
    Contents Factorisation of QuadraticExpression ax2 + bx +c When a ≠ 1 Test for Simple Factors 52
  • 53.
    FACTORISATION OF QUADRATIC EXPRESSIONax2 + bx +c WHEN a ≠ 1 Obtain /ac/ If C is positive, we will select two factors of /ac/ whose sum is equal to /b/. Both of these factors will carry the sign of b. If C is negative, we will select two factors of /ac/ which differ by the values of /b/. The numerically larger one will have the sign of b. the two factors will thus possess opposite signs.  then ax2 + bx +c will now be written as  ax2 + f1x + f2x +c  you will now factorise by grouping. 53
  • 54.
    Factorisation of QuadraticExpression ax2 + bx +c When a ≠ 1  Factorise 6x2 + 11x + 3  ax2 + bx +c  a = 6, b = 11, c = 3  Now /ac/ = /6 × 3/ = /18/ =18  Since c is positive, we are interested in .two factors of /ac/ whose sum is equal to /b/. And the two factors are 2 and 9.  So therefore ax2 + bx +c will now be written as  ax2 + f1x + f2x +c  6x2 + 2x + 9x + 3  Factorise by grouping  (6x2 + 2x) + (9x + 3)  2x (3x + 1) +3 (3x +1)  (2x +3) (3x+1) 54
  • 55.
    Factorisation of QuadraticExpression ax2 + bx +c When a ≠ 1  Factorise 8x2 + 18x −5  ax2 + bx +c  a = 8, b = 18, c = −5  Now /ac/ = /8 × −5 / = /−40/ = 40  Since C is negative, we will select two factors of /ac/ which differ by the values of /b/. The numerically larger one will have the sign of b. And the two factors are + 20 and −2  So therefore ax2 + bx +c will now be written as  ax2 + f1x + f2x +c  8x2 −2x +20x −5  Factorise by grouping  (8x2 −2x) +(20x −5)  2x(4x − 1) +5 (4x − 1)  (2x+5) (4x − 1) 55
  • 56.
    TEST FOR SIMPLEFACTORS Some quadratic equations are not capable of being written as the product of simple factors. i.e. factors where all the coefficients are integers. To determine whether ax2 + bx +c can be factorised into two simple factors. We will first evaluate the expression (b2 −4ac). 56
  • 57.
    Test for SimpleFactors If b2 −4ac is a perfect square; can be written as k2. then ax2 + bx +c can be factorised into simple factors. But if b2 −4ac is not a perfect square; cannot be written as k2. then ax2 + bx +c cannot be factorised into simple factors 57
  • 58.
    Test for SimpleFactors Test for the simple factors of 3x2 − 4x +5 . a=3 b = −4 c=5 Using b2 −4ac , we will have (−4)2 − 4 (3) (5) (−4)2 − 4 × 3 × 5 16 − 60 −44 Note −44 is not a perfect square, thus the expression 3x2 − 4x +5 have no simple factors. 58
  • 59.
    Test for SimpleFactors  Test for the simple factors of 2x2 +5x −3 .  a=2 b = 5 c=−3  Using b2 −4ac , we will have (5)2 − 4 (2) (−3)  (5)2 − 4 × 2 × −3  25 − 4(−6)  25 + 24  49  Note 49 is a perfect square; can be written as 72.  thus the expression 2x2 + 5x −3 can be factorised into simple factors 59
  • 60.
    CONTACT DETAILS  Followthis YouTube link to watch the video on Algebra 1-6  https://www.youtube.com/channel/UC_FYPDg12rH5Ir3s7LLBgeg?view _as=subscriber  Facebook: Adjex Academy  LinkedIn: Adjex Academy  Slideshare: Adjex Academy  Instagram: adjex_academy  E-mail: adjexacademy@gmail.com 60
  • 61.