## Geometry: Common Core (15th Edition)

midpoint = $(-6, -2)$
In this problem, we need to use the midpoint formula. The midpoint can be found using the following formula: midpoint = $(\frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2})$, where $(x_1, y_1)$ and $(x_2, y_2)$ are the endpoints of the line segment. The points we are given are $M (6, -11)$ and $N (-18, 7)$. Let's plug these points into the formula: midpoint = $(\frac{6 + (-18)}{2}, \frac{-11 + 7}{2})$ Use addition to simplify: midpoint = $(\frac{-12}{2}, \frac{-4}{2})$ Divide to simplify: midpoint = $(-6, -2)$