To evaluate the function $f(x) = -8x - 9$ at $x = -3$, substitute $-3$ for $x$ in the function:

$f(-3) = -8(-3) - 9$

Now, calculate step by step:

$f(-3) = 24 - 9 = 15$

So, $f(-3) = 15$.

Would you like more details, or do you have any questions?

Here are some related questions for further practice:

1. Evaluate $f(2)$ for the same function $f(x) = -8x - 9$.
2. Find the value of $f(0)$.
3. If $f(x) = -8x - 9$, what value of $x$ makes $f(x) = 0$?
4. Evaluate the derivative of $f(x) = -8x - 9$.
5. If $g(x) = 5x + 4$, find $f(g(1))$.

Tip: Always substitute the given value carefully to avoid sign errors when evaluating functions.