Answer: B = ( -3 , 2)
Explanation:
You would use a mid point formular because you are trying to find the middle of a line . The midpoint formular is (X1 + X2 , Y1 + Y2 ) 
 /2 /2 
From the information given A is (7 , -2 ) 
If you fill it in it would be 7 + X , -2 + X
 /2 /2 = (2 , 0 ) 
The only posible solution would be 7- 3 /2 , -2 + 2 / 2 
Makeing B (-3, 2).