Question

R is the midpoint of DA⎯⎯⎯⎯⎯. D has coordinates (5,−6), and R has coordinates (9,−2). Identify the coordinates of A.

Answer 1

Explanation:

A(x₁ ,y₁) & D(5 , -6)

Midpoint =
`\left((x_(1)+x_(2))/(2),(y_(1)+y_(2))/(2) \right)`

`R(9,-2)= \left((x_(1)+5)/(2),(y_(1)-6)/(2) \right)`

Compare x and y coordinates of both sides

`(x_(1)+5)/(2)=9` ;
`(y_(1)-6)/(2)=-2`

x₁ + 5 = 18 ; y₁ - 6 = -4

x₁ = 18 - 5 ; y₁ = -4 + 6

x₁ = 13 y₁ = 2

A(13 , 2)