$\begin{array} { l }\frac{ 7 }{ x }=\frac{ 5 }{ 9 },& x≠0\end{array}$
Simplify the equation using cross-multiplication$63=5x$
Swap the sides of the equation$5x=63$
Divide both sides of the equation by $5$$\begin{array} { l }x=\frac{ 63 }{ 5 },& x≠0\end{array}$
Check if the solution is in the defined range$\begin{align*}&x=\frac{ 63 }{ 5 } \\&\begin{array} { l }x=12 \frac{ 3 }{ 5 },& x=12.6\end{array}\end{align*}$