Find the missing endpoint if K is the midpoint LM

Question

L(-9,4) and K(2,-1) Find M

Answer 1

Hi Madison C.

M (13, -6)

Since K is the midpoint of LM you can use the Midpoint formula to solve for the coordinates of the endpoint M.

You are given one endpoint L and the midpoint of LM, K, where

L (-9, 4) and K (2, -1)

Let the coordinates of L = (x_1, y₁)

Let the coordinates of M = (x₂, y₂)

The Midpoint Formula is

(x₁ + x₂)/2 = x coordinate of the Midpoint

(y₁ + y₂)/2 = y coordidnate of the Midpoint

Plug in the coordinates you have to solve for the other endpoint M

(-9 + x₂)/2 = 2

Multilply both sides by 2

-9 + x₂ = 4

Add 9 to both sides of the equation

x₂ =4 + 9 = 13

Just repeat the process for the y₂

(4 + y₂)/2 = -1

4 + y₂ = -2

y₂ = -2 -4

y₂ = -6

I hope you find this useful if you have any questions just send me a message

Answer 2

The left endpoint is at L(-9,4)

The right endpoint is at (x,y)

(-9+x)/2 = 2 --> -9 +x = 4 ---> x = 13

(4+y)/2 = -1 --> 4+y = -2 ---> y = -6

The right endpoint is M(13,-6)