To evaluate $f(6)$, we will substitute $x = 6$ into the function $f(x) = 5x - 20$.

$f(6) = 5(6) - 20 = 30 - 20 = 10$

Therefore, $f(6) = 10$.

Do you need more details or have any questions?

Here are 5 related questions:

1. What would $f(0)$ be for the function $f(x) = 5x - 20$?
2. How does the function $f(x)$ behave as $x \to \infty$?
3. Can you find $g(6)$ for $g(x) = x^2 + 5x - 11$?
4. What is the solution to $f(x) = 0$?
5. How would you graph $f(x) = 5x - 20$?

Tip: When evaluating functions, always substitute the given value of $x$ into the equation and simplify carefully.