## Precalculus (6th Edition)

When $y$ varies directly as $x$, then $y=kx$ where $k$ is the constant of variation. Note that if $k\gt 0$, when the value of $x$ increases, the value of $y$ also increases. When the value of $x$ decreases, the value of $y$ also increases. Thus, the missing expressions in the given statement (in order) are: increases; decreases