Answer:
[tex](f+g)(3)=20[/tex]
Step-by-step explanation:
[tex](f+g)(3)=f(3)+g(3)\\\\=(x^{2} +3x-7)+(5x-3)\\=((3)^2+3(2)-7)+(5(3)-3)\\=(9+6-7)+(15-3)\\=8+12\\=20[/tex]
