I don't know how to multiply this out into a polynomial form. Can anyone show me?
f(x) = (x+3)(x+1)(x-2)(x-5)
(x+3)(x+1) * (x-2)(x-5)
(3x^2+4x+3)(x-2) * (x-5)
That make sense? There are other ways, but they depend on concepts that you may or may not know. This is known as FOIL'ing or distributing.