Question

Point M is the midpoint of AB. The coordinates of point A are (-8, 3) and the coordinates of M are (-2, 1). What are the coordinates of point B?

Answer 1

$\bf \textit{middle point of 2 points }\\ \quad \\ \begin{array}{lllll} &x_1&y_1&x_2&y_2\\ % (a,b) A&({{ -8}}\quad ,&{{ 3}})\quad % (c,d) B&({{ x}}\quad ,&{{ y}}) \end{array}\qquad % coordinates of midpoint \left(\cfrac{{{ x_2}} + {{ x_1}}}{2}\quad ,\quad \cfrac{{{ y_2}} + {{ y_1}}}{2} \right) \\\\\\ \left( \cfrac{x-8}{2}~,~\cfrac{y+3}{2} \right)=\stackrel{M}{(-2,1)}\implies \begin{cases} \cfrac{x-8}{2}=-2\\\\ x-8=-4\\ x=4\\ ------\\ \cfrac{y+3}{2}=1\\\\ y+3=2\\ y=-1 \end{cases}$

Answer 2

B= (4,-1)
I hope this was helpful!