Chapter 10 - Exponents and Radicals - 10.7 The Distance Formula, the Midpoint Formula, and Other Applications - 10.7 Exercise Set - Page 679: 66

$\left( 5,-1 \right)$

Using $\left( \dfrac{x_1+x_2}{2},\dfrac{y_1+y_2}{2} \right)$ or the Midpoint Formula, the midpoint of the segment joining $\left( 1,4 \right) \text{ and } \left( 9,-6 \right),$ is \begin{array}{l}\require{cancel} \left( \dfrac{1+9}{2},\dfrac{4+(-6)}{2} \right) \\\\= \left( \dfrac{10}{2},\dfrac{-2}{2} \right) \\\\= \left( 5,-1 \right) .\end{array}