Answer:
[tex]3x^{3}+3x^{2}-11x+3[/tex]
Step-by-step explanation:
f(x) + g(x) = [tex]8x^{3}+7x^{2}-11x+20-5x^{3}-4x^{2}-17[/tex]
To make this equation a little less long, we combine like terms
[tex](8-5)x^{3}+(7-4)x^{2}-11x+(20-17)[/tex]
or just
[tex]3x^{3}+3x^{2}-11x+3[/tex]
