Question

Factorise the following a. 9x^2 -12x+4 b. x^3+x^2-4x-4​

Answer 1

Answer:

a. ( 3x-2) (3x - 2)

Step-by-step explanation:

a. 9x² - 12x +4

9x² - 6x - 6x +4

3x(3x - 2) - 2(3x - 2)

( 3x-2) (3x - 2)

Answer 2

Answer:

a. (3x - 2)^2

b. (x + 1) (x - 2) (x + 2)

Step-by-step explanation:

a. 9x^2 - 12x + 4 = 9x^2 - 6x - 6x + 4

= 3x(3x - 2) - 2(3x - 2)

= (3x - 2) (3x - 2)

= (3x - 2)^2.

b. x^3 + x^2 - 4x - 4

Putting x = -1 gives -1+1+4-4 = 0, so - 1 is the root of the above polymomial.

we then divide the above polynomial by (x+1), -1 being a root gives (x+1) as a factor.

so,

x^3 + x^2 -4x -4 = (x + 1)(x^2 - 4)

= (x + 1)(x - 2)(x + 2)