[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}\\\\
-------------------------------\\\\
\textit{we also know that }
\begin{cases}
y=-20\\
x=2
\end{cases}\implies -20=k2\implies \cfrac{-20}{2}=k
\\\\\\
-10=k\qquad therefore\qquad \boxed{y=-10x}
\\\\\\
\textit{when x = 14, what is \underline{y}?}\qquad y=-10(14)[/tex]
