C. 0
In this case they are the same number but opposite.
If we were to do 7-7 it is equal 0. When we look at it, there is a 7 and a -7 even though everyone knows that the answer is 0, you can see they look the same. Now, let’s look at the other choices.
A is wrong because -7 + -7 = -14
B is wrong because -7 + 0
D is wrong because 7 + 7 = 14
Hope this helps, have a great day, and stay safe!!
:)
