Question

M(8, 7) is the midpoint of RS. The coordinates of S are (9, 5). What are the coordinates of R?

Answer 1

(7,9)

Explanation:

Let R:(x,y)

(x+9)/2, (y+5)/2 = 8 ,7

x + 9 = 16

x = 7

y + 5 = 14

y = 9

R: (7,9)

Answer 2

M(Mx, My), R(Rx, Ry), S(Sx, Sy)

M is midpoint of RS

=> Rx + Sx = 2Mx => Rx = 2Mx - Sx = 2 x 8 - 9 = 7

=> Ry + Sy = 2My => Ry = 2My - Sy = 2 x 7 - 5 = 9

=> R(7, 9)

Hope this helps!

:)