We are given the function:

$f(x) = 3x - 7$

You are asked to evaluate $f(-6)$.

To do this, substitute $x = -6$ into the function:

$f(-6) = 3(-6) - 7 = -18 - 7 = -25$

Thus, $f(-6) = -25$.

Would you like further explanation or any related questions? Here are 5 more questions to expand on this:

1. What would $f(x)$ equal if $x = 0$?
2. How would you graph the function $f(x) = 3x - 7$?
3. What is the slope of the function $f(x) = 3x - 7$?
4. How does the function $f(x) = 3x - 7$ behave as $x \to \infty$?
5. Can you determine the x-intercept of the function $f(x) = 3x - 7$?

Tip: When evaluating functions, always remember to replace the variable with the given value and follow the order of operations (PEMDAS).