Question

One endpoint of a segment is M(0, 8). The midpoint of the segment is

Q(4, 10). What are the coordinates of the other endpoint?

Answer 1

`~~~~~~~~~~~~\textit{middle point of 2 points } \\\\ M(\stackrel{x_1}{0}~,~\stackrel{y_1}{8})\qquad (\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 + 0}{2}~~~ ,~~~ \cfrac{ y + 8}{2} \right)~~ = ~~\stackrel{\textit{\Large Q}}{(4~~,~~10)}\implies \begin{cases} \cfrac{x+0}{2}=4\\[1em] \boxed{x=8}\\[-0.5em] \hrulefill\\ \cfrac{y+8}{2}=10\\[1em] y+8=20\\ \boxed{y=12} \end{cases}`