We can add, subtract, multiply, and divide functions just like how we add, subtract, multiply, and divide numbers. To find (f + g)(x) from the given functions f(x) and g(x), we just add the two formulas:
(f + g)(x) = f (x) + g(x)
(f + g)(x) = [3x + 1 ] + [x^2 - 6]
Then, we simplify the expressions to
(f + g)(x) = 3x + 1 + x^2 - 6
(f + g)(x) = x^2 + 3x - 5
Therefore our answer is x^2 + 3x - 5