f(x) = x2 + 1 g(x) = 5 – x(f + g)(x) =

To find (f + g)(x), add the two functions: (x² + 1) + (5 − x). Combine the constants, 1 + 5 = 6, and keep the −x term, giving x² − x + 6. This matches choice C.

AI-written and checked against the verified answer.