Answer:
B 5,7
Explanation:
Endpoint B (x,y) (missing therefore I called them x and y)
endpoint A (1,-7)
midpoint M (-2,0)
use your midpoint formula:
x1+x2 , y1+y2
¯¯2¯¯¯ ¯¯2¯¯
(x+1)/2 = -2 (mulitply the 2 on both side )
x+1 = -4 (subtract 1 on both side)
x = -5
(y+-7)/2 = 0 (mulitply the 2 on both side )
y-7 = 0 (add 7 on both side)
y = 7
Endpoint B (-5,7)