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

Answer:

Step-by-step explanation:

A(x₁ ,y₁)   & D(5 , -6)

Midpoint =$\left(\dfrac{x_{1}+x_{2}}{2},\dfrac{y_{1}+y_{2}}{2} \right)$

$R(9,-2)= \left(\dfrac{x_{1}+5}{2},\dfrac{y_{1}-6}{2} \right)$

Compare x and y coordinates of both sides

$\dfrac{x_{1}+5}{2}=9$            ; $\dfrac{y_{1}-6}{2}=-2$

x₁ + 5 = 18            ; y₁ - 6 = -4

      x₁ = 18 - 5     ; y₁       = -4 + 6

      x₁ = 13                 y₁ = 2

A(13 , 2)