Given that M(1,-6) is the midpoint of AB and A(-2,-1) is one endpoint, what is the sum of the coordinates of point B?
Using the midpoint formula
( -2 + x ) / 2 = 1 ( -1 + y) / 2 = -6
-2 + x = 2 -1 + y = -12
x = 4 y = -11
B = (x , y) = ( 4 , -11)
Sum = -7
