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?
x coordinate = [ x - 2 ] / 2 = 1 multiply both sides by 2
x - 2 = 2 add 2 to both sides
x = 4
y coordinate = [ 1 + y ] / 2 = -6 multiply both sides by 2
1 +y = - 12 subtract 1 from both sides
y = -13
So B = ( 4, -13)