# How do you solve b/0.5=9/2.5?

You can multiply $0.5$ on both sides to get:
$\frac{\textcolor{b l u e}{b}}{\cancel{0.5}} \cdot \cancel{0.5} = \frac{9}{2.5} \cdot 0.5$
$= \frac{4.5}{2.5}$
$= \frac{45}{25}$
$= \textcolor{b l u e}{\frac{9}{5}}$