To find \((f + g)(x)\), we need to add the functions \(f(x)\) and \(g(x)\) together.
Given: \[ f(x) = -13x^2 - 17x + 5 \] \[ g(x) = 9x^2 + 8x - 16 \]
Now, we can combine them: \[ (f + g)(x) = f(x) + g(x) \] \[ = (-13x^2 - 17x + 5) + (9x^2 + 8x - 16) \]
Now, let's combine like terms:
-
Combine the \(x^2\) terms: \[ -13x^2 + 9x^2 = -4x^2 \]
-
Combine the \(x\) terms: \[ -17x + 8x = -9x \]
-
Combine the constant terms: \[ 5 - 16 = -11 \]
Putting it all together, we have: \[ (f + g)(x) = -4x^2 - 9x - 11 \]
Thus, the final result is: \[ \boxed{-4x^2 - 9x - 11} \]