To find $(f+g)(x)$, we need to add the functions $f(x)$ and $g(x)$ together.
Given:
$$f(x) = 9^2 + 5x + 4$$
$$g(x) = -8x^2 - 3x - 4$$
To calculate $(f+g)(x)$, we add the corresponding terms of $f(x)$ and $g(x)$ together.
$$(f+g)(x) = f(x) + g(x) = (9^2 + 5x + 4) + (-8x^2 - 3x - 4)$$
Simplifying the expression further:
$$(f+g)(x) = 81 + 5x + 4 - 8x^2 - 3x - 4$$
Combining like terms:
$$(f+g)(x) = -8x^2 + 2x + 81$$
Therefore, $$(f+g)(x) = -8x^2 + 2x + 81$$.
