Answer
variation constant: $\frac{2}{5}$
equation of the variation: $y=\frac{2}{5}x$
Work Step by Step
$y$ varies directly as $x$ so the variation is direct.
The equation of a direct variation is of the form $y=kx$ where $k$ is the constant of variation.
To find the value of $k$ substitute the given values of $x$ and $y$ into $y=kx$ to obtain:
$$y=kx
\\2=k(5)
\\\frac{2}{5}=\frac{k(5)}{5}
\\\frac{2}{5}=k$$
Thus, the equation of the variation is $y=\frac{2}{5}x$.
