Factor polynomial completely

Question

F(x) = x^4 - 2x^3 - 15x^2 - 4x + 20

Answer 1

Show that F(1) = 0 which implies (x-1) is a factor.

Divide by long division to get: x³ - x² - 16x - 20.

Show that F(5) = 0 which implies (x-5) is a factor.

Divide by long division to get x² + 4x + 4 which =(x+2)²

In summary F(x)=(x-1)(x-5)(x+2)²