Question

The midpoint of start overline, AB, end overline
AB
is M, left parenthesis, 2, comma, minus, 2, right parenthesisM(2,−2). If the coordinates of AA are left parenthesis, 5, comma, minus, 7, right parenthesis(5,−7), what are the coordinates of BB?

Answer 1

Let B = (x, y). Midpoint formula gives
( (5 + x)/2, (-7 + y)/2 ) = (2, -2).

So (5 + x)/2 = 2 → 5 + x = 4 → x = -1.
(-7 + y)/2 = -2 → -7 + y = -4 → y = 3.

Therefore B = (-1, 3).