Question

Find the coordinates of R if M(-4, 5) is the midpointof RS and S has coordinates (0, -10).

Answer 1

The general formula for midpoint is

`x_m,y_m=(x_1+x_2)/(2),\text{ }(y_1+y_2)/(2)`

Here coordinates of midpoint M is

`x_m,y_m=(-4,5)`

Coordinates of S is

`x_2,y_2=\text{ }(0,-10)`

Substitute in midpoint formula

`\begin{gathered} -4=(x_1+0)/(2) \\ -4\ast2=x_1 \\ x_1=-8 \\ \\ \\ coordinatey_1 \\ \\ 5=(y_1+(-10))/(2) \\ 5\ast2=y_1-10 \\ 10=y_1-10 \\ y_1=10+10=20 \end{gathered}`

The coordinates of R is x1, y1=(-8,20)