Question

The midpoint of AB is M(-5,1). If the coordinates of A are (-4,-5), what are the coordinates of B?

Answer 1

ANSWER:

The midpoint of AB is M(-5,1). The coordinates of B are (-6, 7)

SOLUTION:

Given, the midpoint of AB is M(-5,1).  

The coordinates of A are (-4,-5),  

We need to find the coordinates of B.

We know that, mid-point formula for two points A$(x_{1}, y_{1})$ and B $(x_{1}, y_{2})$ is given by

$M\left(x_{3}, y_{3}\right)=\left(\frac{x_{1}+x_{2}}{2}, \frac{y_{1}+y_{2}}{2}\right)$

Here, in our problem, $\mathrm{x}_{3}=-5, \mathrm{y}_{3}=1, \mathrm{x}_{1}=-4 \text { and } \mathrm{y}_{1}=-5$

Now, on substituting values in midpoint formula, we get

$(-5,1)=\left(\frac{-4+x_{2}}{2}, \frac{-5+y_{2}}{2}\right)$

On comparing, with the formula,

$\frac{-4+x_{2}}{2}=-5 \text { and } \frac{-5+y_{2}}{2}=1$

$-4+\mathrm{x}_{2}=-10 \text { and }-5+\mathrm{y}_{2}=2$

$\mathrm{x}_{2}=-6 \text { and } \mathrm{y}_{2}=7$

Hence, the coordinates of b are (-6, 7).