[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\\
variation
\end{array}\\\\
-------------------------------\\\\
\textit{we know that }
\begin{cases}
y=7\\
x=2
\end{cases}\implies 7=\cfrac{k}{2}\implies 7\cdot 2=k\implies 14=k
\\\\\\
thus\qquad \qquad \boxed{y=\cfrac{14}{x}}[/tex]