Factor by grouping: x3+x2−4x−4x^3 + x^2 - 4x - 4x3+x2−4x−4.
(x+1)(x−2)(x+2)(x + 1)(x - 2)(x + 2)(x+1)(x−2)(x+2)
(x−1)(x2+4)(x - 1)(x^2 + 4)(x−1)(x2+4)
(x+1)(x2−4x)(x + 1)(x^2 - 4x)(x+1)(x2−4x)
(x−1)(x+2)(x−2)(x - 1)(x + 2)(x - 2)(x−1)(x+2)(x−2)