If (-9,-1) is the endpoint of a line segment, and (8,14) is its midpoint- find the other endpoint

Please explain Step by Step, and show me the formula you used.

Let (x,y) be the other endpoint.
( (x + -9)/2 , (y + -1)/2 ) = (8,14)
(x - 9)/2 = 8
x - 9 = 16
x = 25
(y - 1)/2 = 14
y - 1 = 28
y = 29

Note that the coordinates of the midpoint are the average of the coordinates of the two endpoints.

If we let (x, y) be the other endpoint, we see that the average of the x-coordinates of the two endpoints is (x - 9)/2 and the average of the y-coordinates of the two endpoints is (y - 1)/2.

Since these averages equal 8 and 14, respectively, we have:
(x - 9)/2 = 8 and (y - 1)/2 = 14 ==> x = 25 and y = 29.

Therefore, the coordinates of the other endpoint is (25, 29).

I hope this helps!

x coordinate
midpoint = 8 end point is -9
8 - -9 = difference between the two = 17 units
therefore add 17 to 8 for the other x coordinate = 25

y coordinate
midpoint = 14 end point - 1
difference = 14 - -1 =15 units
add 15 to 14 for the other y coordinate = 29

Let the endpoint have coordinates (x,y):

(x - 9)/2 , (y - 1)/2 = 8, 14

(x - 9)/2 = 8 --> x = 25

(y - 1)/2 = 14 --> y = 29

Other endpoint: (25, 29)

x_avg = [x2 + x1]/2
8 = [x2 + (-9)]/2
16 = x2 - 9
x2 = 25

y_avg = [y2 + y1]/2
14 = [y2 + (-1)]/2
28 = y2 - 1
y2 = 29

(25, 29)