Answer:
5 + (-5) and 8 + (-8)
Step-by-step explanation:
Sum of zero means when you add them you get 0
so the others are wrong
-5 + (-5) = -10 because you have -5 and you add another -5
-12 + (-12) = -24 you start with -12 and you add another -12
Think of positive and negative numbers like floors in a building. Positive numbers are the stories and the negative numbers are the basement and sub-basement, zero is the ground level. So for 5 + (-5) you go up 5 floors, then you go down 5 floors. you end up on the ground level, 0.
