Question

How do you find the missing coordinate if the 1st coordinate is (12, -8) and the midpoint is (3, 18)?

Answer 1

`(-6,44)`

Explanation:

`"the coordinates of the midpoint are the average of the"`
`"coordinates of the endpoints"`

`"here one endpoint is "(12,-8)`

`"let the endpoint to be found "=(x,y)`

`rArr1/2(12+x)=3larrcolor(blue)"x-coordinate of midpoint"`

`"multiply both sides by 2"`

`rArr12+x=6rArrx=6-12=-6`

`rArr1/2(-8+y)=18larrcolor(blue)"y-coordinate of midpoint"`

`"multiply both sides by 2"`

`rArr-8+y=36rArry=36+8=44`

`rArr"coordinates of missing endpoint "=(-6,44)`