Find the sum of 18 + (-15).

A. 3

B. - 3

C. 33

D. - 33

Answer: 3

Step-by-step explanation: To find the sum of these two numbers, remember that adding a negative is exactly the same thing as subtracting a positive. In other words, when we see 18 + (-15), we can change the problem so it's easier to understand and we will change in to 18 - 15.

Now, this is just basic subtraction.

18 - 15 = 3

Therefore, 18 + (-15) = 3