To answer this question, we may need to use the FOIL method.
FOIL-- First, Outer, Inner Last.
Basically, it's a distributive property.
So:
(x+5)(x-2)
= x^2 -2x+5x-10
= x^2 +3x -10
Hope this helps!
If you have any questions, please put it in the comment section below.