To find the value of $f(3)$, we need to substitute $x = 3$ into the given equation:

$f(x) = 2x + 4$

Now substitute $x = 3$:

$f(3) = 2(3) + 4$

This simplifies to:

$f(3) = 6 + 4 = 10$

So, the correct equation to determine the value of $f(3)$ is:

C. $f(3) = 2(3) + 4$

Further Questions:

1. How do you find $f(4)$ using the equation $f(x) = 2x + 4$?
2. What would be the value of $f(0)$?
3. How would the equation change if $f(x) = 3x + 5$?
4. What happens to the graph of $f(x) = 2x + 4$ when $x$ increases?
5. How does the value of $f(x)$ change if you subtract 2 from both sides of the original equation?

Tip:

Always substitute the value of $x$ directly into the equation to evaluate $f(x)$ at any specific point.