Question

M(1,3) is the midpoint of RS. If S has coordinates (8,3) find the coordinates of R

Answer 1

let r=(x,y)
m=(r+s)/2
(1,3)=([x+8]/2 , [y+3]/2)

a) 1 = (x+8)/2
2 =x+8
x = -6
b) 3 = (y+3)/2
6 = y+3
y = 3

Answer 2

The answer would be (-6,3)