1. Identify the two integers involved in the subtraction:
(-3) and 12.
2. Understand that subtracting 12 from -3 means adding the additive inverse of 12 to -3:
-3 - 12 = -3 + (-12).
3. Perform the addition of the two negative numbers:
-3 + (-12) = -3 - 12.
4. Calculate the result:
-3 - 12 = -15.
So, the answer is:
-15