Question

Given on endpoint D (-4, 8) and midpoint M (-1, 7). Find the other endpoint.

Answer 1

`~~~~~~~~~~~~\textit{middle point of 2 points } \\\\ D(\stackrel{x_1}{-4}~,~\stackrel{y_1}{8})\qquad E(\stackrel{x_2}{x}~,~\stackrel{y_2}{y}) \qquad \left(\cfrac{ x_2 + x_1}{2}~~~ ,~~~ \cfrac{ y_2 + y_1}{2} \right) \\\\\\ \left(\cfrac{ x -4}{2}~~~ ,~~~ \cfrac{ y +8}{2} \right) \implies \stackrel{\textit{\LARGE M}}{(-1~~,~~7)} \\\\[-0.35em] ~\dotfill\\\\ \cfrac{ x -4}{2}=-1\implies x-4=-2\implies \boxed{x=2} \\\\\\ \cfrac{ y+8}{2}=7\implies \implies y+8=14\implies \boxed{y=6}`