what are the rational zeros of x^3 - 12x - 16

Answer 1

The first root I can guess is +4
so divide (x^3 + 0 x^2 - 12 x - 16
by (x-4)
I get
(x-4)(x^2 + 4 x + 4 )
(x-4)(x+2)(x+2)
so three roots are:
4
-2
-2