Question

The midpoint of MO is N (15, 12). M is at (-4, 9) what is the coordinate of O?

Answer 1

The formula of the midpoint of MO:

`N\left((x_M+x_O)/(2);\ (y_M+y_O)/(2)\right)`

We have N(15; 12) and M(-4; 9), O(x; y). Substitute:

`(15;\ 12)=\left((-4+x)/(2);\ (9+y)/(2)\right)\\\\(-4+x)/(2)=15\ \ \ \ |\cdot2\\\\-4+x=30\ \ \ |+4\\\\x=34\\\\(9+y)/(2)=12\ \ \ \ |\cdot2\\\\9+y=24\ \ \ |-9\\\\y=15`
Your answer is
`N(34;\ 15)`