Factorisation

Question 1

What is factorisation?

Answer 1

Usually means putting back in the brackets.

Question 2

What numbers are common to all terms in the original expression?

Answer 2

The numbers outside the brackets.

Question 3

Factorising quadrant equations

(X’2 + ax + b)

Answer 3

Seek to find a pair of the numbers which are the product of b and the sum of ax

Question 4

The difference of two squares

Answer 4

The technique is in the identity

a2 - b2 = (a+b)(a-b)
n2 -36 = (n+6)(n-6)

Question 5

How to factorise

n’2 - 36

Answer 5

Find the square root of 36 and then apply the usual method

n+6)(n-6

Question 6

Factorise this perfect square

(a+b)’2

Answer 6

a’2 + 2ab + b’2

Question 7

Factorise this perfect square

(a-b)’2

Answer 7

a’2 - 2ab + b’2

Question 8

Factorise

2x+9x+4

Answer 8

Multiply the number before the first x by the the last number.

Use usual method

Then cancel down

2x+9x+4
2x+9x+8
(2x+1) (2x+8)
(2x+1) (x+4)