[tex]\bf \qquad \qquad \textit{inverse proportional variation}\\\\
\textit{\underline{y} varies inversely with \underline{x}}\qquad \qquad y=\cfrac{k}{x}\impliedby
\begin{array}{llll}
k=constant\ of\\
\qquad variation
\end{array}\\\\
-------------------------------\\\\
\textit{we also know that }
\begin{cases}
y=4.5\\
x=3
\end{cases}\implies 4.5=\cfrac{k}{3}\implies 4.5(3)=k
\\\\\\
13.5=k\qquad therefore\qquad \boxed{y=\cfrac{13.5}{x}}[/tex]
