Question

If y varies inversely as x find the constant of variation and that inverse of variation
Y=120 when x=7

Answer 1

$\bf \begin{array}{llllll} \textit{something}&&\textit{varies inversely to}&\textit{something else}\\ \quad \\ \textit{something}&=&\cfrac{{{\textit{some value}}}}{}&\cfrac{}{\textit{something else}}\\ \quad \\ y&=&\cfrac{{{\textit{k}}}}{}&\cfrac{}{x} \\ &&y=\cfrac{{{ k}}}{x} \end{array}\\\\ -----------------------------\\\\ \textit{now, we know that } \begin{cases} y=120\\ x=7 \end{cases}\implies 120=\cfrac{k}{7}$

solve for "k", to find "k" or "constant of variation"