Answer: 2x^2 + x - 8
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Work Shown:
(f + g)(x) = f(x) + g(x)
(f + g)(x) = x^2+x+1 + g(x) ............... plug in f(x) = x^2+x+1
(f + g)(x) = x^2+x+1 + x^2-9 ........... plug in g(x) = x^2-9
(f + g)(x) = (x^2+x^2)+x+(1-9)
(f + g)(x) = 2x^2+x-8
