Answer:
3x^2 + x + 1
Explanation:
(f+g)(x) just wants you to add f(x) and g(x) together.
If f(x) = 3x^2 - 1 and g(x) = x + 2, you can add them together like so:
(3x^2 - 1) + (x + 2)
Combine like terms and add -1 and 2 together.
3x^2 + 1 + x
Rewrite this expression so it is in standard form (the exponents are in order from greatest to least).
3x^2 + x + 1