Answer:
endpoint for B is (10,-2)
Explanation:
M={(x1+x2)/2,(y1+y2)/2}
(4,2)={-2+x2/2,6+y2/2)
By equating the x coordinates
4=-2+x2/2
8=-2+x2
8+2=x2
x2=10
By equating the y coordinates
2=6+y2/2
4=6+y2
4-6=y2
y2=-2
Therefore the endpoint for B is (10,-2)