The coordinates of the midpoint of line segment AB:
[tex]A(x_A;\ y_A);\ B(x_B;\ y_B)\\\\\left(\dfrac{x_A+x_B}{2};\ \dfrac{y_A+y_B}{2}\right)[/tex]
[tex]A(4;\ 7);\ B(-6;\ 6)[/tex]
subtitute
[tex]\left(\dfrac{4+(-6)}{2};\ \dfrac{7+6}{2}\right)=\left(\dfrac{-2}{2};\ \dfrac{13}{2}\right)=\boxed{(-1;\ 6.5)}[/tex]
