Midpoint Help / Math
posted by Andy .
M(4,2) is the midpoint of RS. If S has coordinates (2,5), find the coordinates of R.

Midpoint formula:
M = [ (x1 + x2)/2 , (y1 + y2)/2]
(4,2) = [ (2 + x)/2 , (5, + y)/2 ]
4 = (2 + x)/2 and 2 = (5 + y)/2
8 = 2 + x. and 4 = 5 + y
6 = x. and 1 = y
Coordinates of R (6, 1)