What is the value of the expression 15 - 9 + 3?

To evaluate the expression 15 - 9 + 3, you follow the order of operations, although in this case, you simply perform the operations from left to right since there are only addition and subtraction involved.

First, subtract 9 from 15:

15 - 9 = 6

Next, take that result and add 3:

6 + 3 = 9

Thus, the final value of the expression is 9. This aligns with the third choice, confirming its correctness. Therefore, option B, which states 8, does not accurately represent the solution to the expression. The correct answer is indeed 9, which emphasizes the importance of careful calculation in arithmetic expressions.