To evaluate the function $f(x) = -8x - 4$ at $x = 9$, substitute $9$ for $x$ in the function:

$f(9) = -8(9) - 4$

$f(9) = -72 - 4$

$f(9) = -76$

So, the answer in function notation is $f(9) = -76$.

Would you like more details on this process or have any questions?

Here are 5 related questions:

1. What is $f(-2)$ for the function $f(x) = -8x - 4$?
2. If $f(x) = -8x - 4$, what is $x$ when $f(x) = 0$?
3. How does the function $f(x) = -8x - 4$ affect the slope and intercept of the line compared to $y = x$?
4. What is the y-intercept of the function $f(x) = -8x - 4$?
5. How would you graph the function $f(x) = -8x - 4$ on a coordinate plane?

Tip: Always simplify step by step when evaluating functions to avoid errors.