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

1 Answer
Apr 13, 2018

(-6,44)(6,44)

Explanation:

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

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

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

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

"multiply both sides by 2"multiply both sides by 2

rArr12+x=6rArrx=6-12=-612+x=6x=612=6

rArr1/2(-8+y)=18larrcolor(blue)"y-coordinate of midpoint"12(8+y)=18y-coordinate of midpoint

"multiply both sides by 2"multiply both sides by 2

rArr-8+y=36rArry=36+8=448+y=36y=36+8=44

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