can someone help my sister with this? i don't really know how to help her so she can understand...

Answer:
43a) -2
43b) 42
43c) -3.4
Step to step explanation:
43a) Look at the middle
43b) 17 - (-25) = 42
43c) add all and then divide by 7 to get -3.4
(Im not to sure bout the last one but the others im sure. But u hope this helps <3)
Answer: Not sure exactly cause im struggling to see but..
43a) is -3
43b) is 17
43c) is 12
Im not sure if this is right but im think it is (/ >_</)