Subtracting a negative is just like adding a positive. A way to think about this is that the negative cancel each other out are you left with a positive number.
When you are subtracting a negative number, it is the same as adding a positive. We can re-write the expression as:
-87 + 82
When adding a negative and positive number, the one with the larger absolute value controls what sign the sum has. In this case the sum would be negative because 87 > 82. Also, we would subtract these absolute values: 87-82 = 5. This has to be negative, meaning the answer is -5.
