From the problem :
[tex]\frac{\frac{r-5}{9r}}{\frac{5-r}{3r^2}}[/tex]
We can rewrite the expression as multiplication :
[tex]\begin{gathered} \frac{r-5}{9r}\times\frac{3r^2}{5-r} \\ \Rightarrow\frac{-(5-r)}{9r}\times\frac{3r^2}{5-r} \\ \Rightarrow-\frac{r}{3} \end{gathered}[/tex]
The answer is C -r/3
