How do you evaluate the function rule for f(x) = 3x when x = 5?

To evaluate the function rule for f(x) = 3x when x = 5, you simply substitute the value of x into the function.

Start with the function definition:

f(x) = 3x

Now replace x with 5:

f(5) = 3 * 5

Now perform the multiplication:

f(5) = 15

Therefore, the evaluated value of the function f(x) at x = 5 is 15. This means that when you input 5 into the function, the output will be 15.