9 - (-15) =

9 - (-15) = 24

To subtract a negative number, you can follow these steps:

Step 1: Keep the first number the same. In this case, the first number is 9.

Step 2: Change the minus sign (-) to a plus sign (+). So, -(-15) becomes +15.

Step 3: Add the two numbers together. So, 9 + 15 = 24.

Therefore, 9 - (-15) = 24.