If x = 4, what is the value of 2x + 5?

To find the value of the expression 2x + 5 when x = 4, you start by substituting 4 for x in the expression.

First, calculate 2 times x:

2 * 4 = 8.

Next, add 5 to this result:

8 + 5 = 13.

Therefore, when x is 4, the value of 2x + 5 is 13. This explains why the correct answer is the option that corresponds to this value. The process involves straightforward arithmetic and demonstrates the importance of following the order of operations and accurately substituting values into expressions.