To find the value of the function $f(x) = 5x + 2$ at $x = 3$, substitute $x = 3$ into the function.

$f(3) = 5(3) + 2$

Calculate this:

$f(3) = 15 + 2 = 17$

The value of the function at 3 is 17.

Would you like further details on this process?

Here are some related questions to consider:

1. What would be the value of $f(x)$ at $x = 4$?
2. How would the value change if the function were $f(x) = 5x - 2$ instead?
3. What is the slope of the function $f(x) = 5x + 2$?
4. How would you find the x-value if $f(x) = 22$?
5. What would the function look like graphically, and where would the point (3, 17) appear on it?

Tip: Substitute values directly into functions to find specific outputs quickly.