The midpoint formula is as follows
[tex]M=(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2})[/tex]
Plug in the information we know.
[tex](1,-2)=(\frac{7+x_2}{2},\frac{2+y_2}{2})[/tex]
Solve for [tex]x[/tex]
[tex]1=\frac{7+x_2}{2}[/tex]
[tex]2=7+x_2[/tex]
[tex]x_2=-5[/tex]
Solve for [tex]y[/tex]
[tex]-2=\frac{2+y_2}{2}[/tex]
[tex]-4=2+y_2[/tex]
[tex]y_2=-6[/tex]
The other endpoint of the segment is [tex](-5,-6)[/tex]
Hope this helps.
頑張って!
