Need help finding the x-intercepts

Question

y=x^3+x^2-100x-100
I know that the answer is (10,0),(-10,0),(-1,0) I don't understand how to get (-10,0) and (10,0)

Answer 1

if you rearrange things a bit, you see

x^3-100x + x^2-100
= x(x^2-100) + 1(x^2-100)
= (x+1)(x^2-100)
= (x+1)(x-10)(x+10)