[tex]\bf \qquad \qquad \textit{direct proportional variation}
\\\\
\textit{\underline{y} varies directly with \underline{x}}\qquad \qquad y=kx\impliedby
\begin{array}{llll}
k=constant\ of\\
\qquad variation
\end{array}\\\\
-------------------------------\\\\
\stackrel{(-3~~,~~2)}{\textit{we also know that }}
\begin{cases}
x=-3\\
y=2
\end{cases}\implies 2=k(-3)\implies \cfrac{2}{-3}=k[/tex]
