## Precalculus (6th Edition) Blitzer

$\frac{x_1+x_2}{2}$; $\frac{y_1+y_2}{2}$
RECALL: The midpoint of the points $(x_1, y_1)$ and $x_2, y_2)$ is given by the formula: $\text{midpoint} =\left(\frac{x_1+x_2}{2}, \frac{y_1+y_2}{2}\right).$ Thus, the missing expressions in the given statement are: $\frac{x_1+x_2}{2}$; $\frac{y_1+y_2}{2}$