Question

The midpoint QR is M (-1,2). One endpoint is R (3,4). Find the coordinates of the other endpoint.

Answer 1

M = (x₁ + x₂)/2 , (y₁ + y₂)/2

(-1, 2) =
`(3 + x)/(2) , (4 + x)/(2)`

At this point, it is easier to separate the x's and y's into two different equations:

x's: -1 =
`(3 + x)/(2)`

-2 = 3 + x

-5 = x

y's: 2 =
`(4 + x)/(2)`

4 = 4 + x

0 = x

Answer: (-5, 0)