Answer
$$ l=\frac{A}{w}=\frac{414}{18.0}=23$$
Work Step by Step
To solve the given equation for $l$, we divide both sides by $w$ and then we substitute the given values to get the value of $l$ as follows
$$\frac{A}{w}= \frac{wl}{l}\Longrightarrow l=\frac{A}{w}\\
\Longrightarrow l=\frac{A}{w}=\frac{414}{18.0}=23$$
