Question

M is the midpoint of the line AB. Endpoint A is (4,2). midpoint M is (6,0). find endpoint B.

Answer 1

$\begin{gathered} \text{ If A= (x1,y1) and B=(x2,y2) then the midpoint M has coordinates} \\ M=(\frac{x_1+x_2_{}}{2},\frac{y_1+y_2}{2}_{}) \\ \text{ Since M=(6,0) and A=(4,2)} \\ 6=\frac{4+x_2}{2},0=\frac{2+y_2}{2} \\ So\text{ } \\ 6\cdot2=4+x_2\text{ And }0=2+y_2 \\ 12-4=x_2\text{ And }-2=y_2_{} \\ x_2=8,y_2=-2 \\ B=(8,-2) \end{gathered}$

So the answer is B=(8,-2)