College Math Placement Practice Test 2026 - Free College Math Questions and Study Guide

To find the value of f(3) when given the function f(x) = 2x + 1, you need to substitute the value of x with 3 in the function.

Start with the function:

f(x) = 2x + 1

Now replace x with 3:

f(3) = 2(3) + 1

Next, perform the arithmetic:

First, calculate 2 times 3, which equals 6. Then, add 1 to this result:

f(3) = 6 + 1 = 7

Therefore, the correct value of f(3) is 7. This means that option C is the correct answer.