## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$\left( \dfrac{5}{2},\dfrac{7\sqrt{3}}{2} \right)$
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 $\left( 9,2\sqrt{3} \right) \text{ and } \left( -4,5\sqrt{3} \right),$ is \begin{array}{l}\require{cancel} \left( \dfrac{9+(-4)}{2},\dfrac{2\sqrt{3}+5\sqrt{3}}{2} \right) \\\\= \left( \dfrac{5}{2},\dfrac{7\sqrt{3}}{2} \right) .\end{array}