Question

The midpoint of AB is M(-1,7). If the coordinates of A are (4,8), what are the coordinates of B?

Answer 1

Given

midpoint of AB is M(-1,7)

coordinates of A (4,8)

Find

coordinates of B

Explanation

as we know that corodinate of midpoint is given by

$x=\frac{x_1+x_2}{2},y=\frac{y_1+y_2}{2}$

so ,

so

$\begin{gathered} -1=\frac{4+x_2}{2} \\ x_2=-6 \end{gathered}$

and

$\begin{gathered} 7=\frac{8+y_2}{2} \\ y_2=6 \end{gathered}$

Final Answer

Therefore , the coordinates of B are (-6 , 6)