Answer: x^2+3x-5
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Work Shown:
(f+g)(x) = f(x) + g(x)
(f+g)(x) = [ f(x) ] + [ g(x) ]
(f+g)(x) = [ 3x+1 ] + [ x^2-6 ]
(f+g)(x) = 3x+1 + x^2-6
(f+g)(x) = x^2 + 3x + (1 - 6)
(f+g)(x) = x^2 + 3x - 5