Find a polynomial function of degree 3 with -2, 3, 5 as zeros

So theyre trying to scare you in this question by giving you the zeros to an already existing function. Basically if x = 1, than the reverse function of this is (x-1)
using that, we can say that the zero or "root" "-2" is equal to (x+2)same with 3, we can say (x-3)= x = 3 and with five, (x-5)= x = 5
so, we have those functions, we can multiply them to eachother to work backwards.(x+2)(x-3)(x-5) =(x^2-x-9)(x-5) =x^3 - 6x^2 - 4x + 45 
please ask if you have questions