Answer
$\left(\dfrac{-2}{5},\dfrac{1}{10}\right)$
Work Step by Step
The midpoint of the two points $(x_1,y_1)$ and $(x_2,y_2)$ is the point $\left(\dfrac{x_1+x_2}{2},\dfrac{y_1+y_2}{2}\right)$
$\left(\dfrac{\dfrac{-2}{5}+\dfrac{-2}{5}}{2},\dfrac{\dfrac{7}{15}+\dfrac{-4}{15}}{2}\right) = \left(\dfrac{-2}{5},\dfrac{1}{10}\right)$