[tex]\bf \textit{middle point of 2 points }\\ \quad \\
\begin{array}{lllll}
&x_1&y_1&x_2&y_2\\
% (a,b)
&({{ 5}}\quad ,&{{ -9}})\quad
% (c,d)
&({{ -2}}\quad ,&{{ -2}})
\end{array}\qquad
% coordinates of midpoint
\left(\cfrac{{{ x_2}} + {{ x_1}}}{2}\quad ,\quad \cfrac{{{ y_2}} + {{ y_1}}}{2} \right)
\\\\\\
\left( \cfrac{-2+5}{2}~~,~~\cfrac{-2-9}{2} \right)[/tex]
