Answer:
Step-by-step explanation:
Well you have one of the roots -- -10. Just by looking at it, -1 would seem to be another x intercept.
f(x) = (-1)^3 + 13(-1)^2 + 32(-1) + 20
f(x) = -1 + 13 - 32 + 20
f(x) = 0
So - 1 is also a root.
You should try -2
-2 * -10 - 1 = - 20
f(-2) = (-2)^3 + 13(-2)^2 + 32(-2) + 20
f(-2) = -8 + 13 * 4 - 32(2) + 20
f(-2) = - 8 + 52 - 64 + 20
f(-2) = -72 + 72
f(-2) = 0
The zeros are
x = -10
x = -1
x = -2
