Question

By using factor theorem, factorise : x3+x2-4x-4

Answer 1

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

Answer 2

If x= -2, -8+4+8-4 =0.

Hence, x+2 is a factor.

=> x^3+x^2-4x-4

=> x^2(x+2)-x(x+2)-2(x+2)

=> (x+2) (x^2-x-2)

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

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

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