Answer:
-2+(-7)= -2-7
Step-by-step explanation:
Let's cross out the ones that are wrong.
-2+(-7) -> The - on the 7 overpowers the addition sign.
-2-(-7)
= -2+7
2-7 -> This doesn't have a negative in front of the 2.
2+7= This doesn't have a negative in front of the 2.
