Answer:
x^3 + 2x^2 - 19x - 20
Step-by-step explanation:
Just use factored form to make them zeros, therefore making them x intercepts.
-1 --> x + 1
4 --> x - 4
-5 --> x + 5
(x + 1)(x - 4)(x + 5) = 0
Now multiply this out with a Punnett square.
After that, the result is...
x^3 + 2x^2 - 19x - 20