Question

The midpoint of AB is M(1,-2). If the coordinates of A are (-3,-8) , what are the coordinates of B ?

Answer 1

Answer:

Explanation:

The midpoint of two points on the coordinate plane is obtained using the formula

$\text{Midpoint}=(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2})$

Substituting the given points, we have:

$(1,-2)=(\frac{-3+x_2}{2},\frac{-8+y_2}{2})$

We can then solve for the unknowns.

$\begin{gathered} \frac{-3+x_2}{2}=1 \\ -3+x_2=2 \\ x_2=2+3 \\ x_2=5 \end{gathered}$

Similarly:

$\begin{gathered} \frac{-8+y_2}{2}=-2 \\ -8+y_2=-4 \\ y_2=-4+8 \\ y_2=4 \end{gathered}$

The coordinates of B are: (5, 4).