Answer
$y=117$
Work Step by Step
To find out the solution we need to follow the 3-step procedure:
Step (1). As $y$ varies directly as $x$ varies, we have
$y=kx$
Here $k$ is a constant.
Step (2)
Substitute $x=5$ and $y=45$ in $y=kx$ to find the value of k.
$\begin{align}
& 45=k\left( 5 \right) \\
& \frac{45}{5}=k \\
& k=9 \\
\end{align}$
Step (3). Substitute $k=9$ and x = 13 in $y=kx$.
$\begin{align}
& y=9\times 13 \\
& y=117 \\
\end{align}$
