Find a cubic function with the given zeros.

We have

(x +2) (x - 5) ( x + 6)

[ x^2 + 2x - 5x - 10 ]  [ x + 6 ]

[ x^2 - 3x - 10] [ x + 6 ] 

x [ x^2 - 3x  - 10 ]  +  6 [ x^2 - 3x - 10 ]   

x^3 - 3x^2 - 10 x  + 6x^2 - 18x - 60        combine like terms

x^3 + 3x^2 - 28x - 60