Given the midpoint and one of the endpoints, find the other endpoint of the segment

Midpoint formula : (x1 + x2) / 2, (y1 + y2) / 2
(6,8)x1 = 6 and y1 = 8
(x,y)     x2 = x and y2 = y
now we sub
(6 + x)/2 , (8 + y)/2 = 3/2

(6 + x) / 2 = 3
6 + x = 3 * 2
6 + x = 6
x = 6 - 6
x = 0

(8 + y) / 2 = 2
8 + y = 2 * 2
8 + y = 4
y = 4 - 8
y = -4

so ur other endpoint is (0,-4) <==

the others u can do the same waybut I am gonna skip a few steps on the rest of them

m (-3,7) , endpoint (0,2)
(0 + x)/2 = -3x = -6
(2 + x) / 2 = 7y = 12
other endpoint is (-6,12) <==

m (-2,4), endpoint (5,-5)
(5 + x) / 2 = -2x = -9
(-5 + y) / 2 = 4y = 13
other endpoint is (-9,13) <==

m (0,0), endpoint (-2,2)
(-2 + x)/2 = 0x = 2
(2 + y) / 2 = 0y = -2
other endpoint is (2,-2) <==