The function given in the image is:

$f(x) = -2x + 4$

To find $f(4)$, substitute $x = 4$ into the function:

$f(4) = -2(4) + 4$

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

So, $f(4) = -4$.

Would you like any further explanation on this? Here are a few related questions:

1. How do you find the value of a function for a given input?
2. What is the slope of the function $f(x) = -2x + 4$?
3. How would the graph of $f(x) = -2x + 4$ look like?
4. What would $f(x) = -2x + 4$ become if you change the slope to 3?
5. How do you determine the x-intercept of the function $f(x) = -2x + 4$?

Tip: When evaluating a function at a specific value, carefully substitute the value into the function and simplify step by step.