Answer:
Step-by-step explanation:
(f + g)(x) simply means that you are adding together the 2 functions that are written in terms of x.
[tex]x^3-x+x^3+2x^2-10[/tex]
The only like terms we have there are the x-cubed's, so
[tex]2x^3+2x^2-x-10=(f+g)(x)[/tex]