Question

Factor by grouping x^3−4x^2−4x+16



(x+4)(x+2)


(x+4)(x2−4)


(x−4)(x2−4)


(x−4)(x−2)

Answer 1

(x^3 - 4x^2) + (-4x + 16)

Taking out the common factor from the first two terms:

x^2(x - 4) - 4x + 16

Taking out the common factor from the last two terms:

x^2(x - 4) - 4(x - 4)

Factoring out (x - 4) from both terms:

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

So the correct factorization is (x - 4)(x + 2)(x - 2)