Answer
$(3,0)$
Work Step by Step
We know that the midpoint of the line segment whose endpoints are $(x_{1},y_{1})$ and $(x_{2},y_{2})$ is the point with coordinates $(\frac{x_{1}+x_{2}}{2},\frac{y_{1}+y_{2}}{2})$.
Therefore, a line with endpoints (7, 3) and (-1, -3) will have a midpoint of $(\frac{7+(-1)}{2},\frac{3+(-3)}{2})=(\frac{6}{2},\frac{0}{2})=(3,0)$.
