Question

How do you factor `x^3-2x-21`?

Answer 1

`(x^2+3x+7)(x-3)`

Explanation:

`x^3-2x-21 = x^3-3x^2+3x^2-9x+7x-21=x^2(x-3)+3x(x-3)+7(x-3)=(x^2+3x+7)(x-3)`[Ans]