Question

P(-9, -10) and Q(-9, 6) are the endpoints of a line segment. What is the midpoint M of that line segment?

Answer 1

The formula of the coordinates of a midpoint:

`M\left((x_1+x_2)/(2);\ (y_1+y_2)/(2)\right)`

We have:

`P(-9,\ -10)\to x_1=-9,\ y_1=-10\\\\Q(-9,\ 6)\to x_2=-9,\ y_2=6`

Substitute:

`(-9+(-9))/(2)=(-18)/(2)=-9\\\\(-10+6)/(2)=(-4)/(2)=-2`

Answer:
`M(-9,\ -2)`