The function given in the image is:

$f(x) = 2x - 8$

We are asked to find the value of $f(-3)$. To do this, substitute $x = -3$ into the function:

$f(-3) = 2(-3) - 8$

Simplifying:

$f(-3) = -6 - 8 = -14$

Thus, the value of $f(-3)$ is $\boxed{-14}$.

Would you like a more detailed explanation, or do you have any questions?

Here are some related questions:

1. What is $f(0)$ for the same function?
2. How would you solve for $x$ if $f(x) = 0$?
3. Can you graph $f(x) = 2x - 8$ and identify its slope and y-intercept?
4. What is the inverse of the function $f(x) = 2x - 8$?
5. How does changing the coefficient of $x$ affect the function?

Tip: Always double-check your substitutions when evaluating a function at a specific point to avoid errors.