Question

Express the polynomial as a product of linear factors f(x)=2x^3+4x^2-2x-4

Answer 1

$f(x)=2x^3+4x^2-2x-4=2(x^3+2x^2-x-2)\\\\=2[x^2(x+2)-1(x+2)]=2(x+2)(x^2-1)=2(x+2)(x^2-1^2)\\\\\boxed{f(x)=2(x+2)(x-1)(x+1)}\\\\Used\ (a-b)(a+b)=a^2-b^2$