You have the following functions:
[tex]\begin{gathered} f(x)=x \\ g(x)=x+13 \end{gathered}[/tex]In order to calculate (f+g)(-3), proceed as follow:
- Sum f(x) and g(x):
[tex](f+g)(x)=f(x)+g(x)=x+x+13=2x+13[/tex]- Next, replace x=-3 into the previous result and simplify:
[tex](f+g)(-3)=2(-3)+13=-6+13=7[/tex]Hence, the result is (f+g)(-3) = 7