Answer
The domain of the function is the set of real numbers less than or equal to $\frac{5}{2}$.
Work Step by Step
$y=\sqrt -2x+5$
The radicand cannot be negative.
$ -2x+5 \geq 0$
$-2x \geq -5$
$x \leq \frac{5}{2}$
The domain of the function is the set of real numbers less than or equal to $\frac{5}{2}$.
