\[\boxed{\text{5.518.}}\]
\[\frac{9}{10} \rightarrow \frac{10}{9};\]
\[7 \rightarrow \frac{1}{7};\]
\[\frac{14}{3} \rightarrow \frac{3}{14};\]
\[\frac{7}{11} \rightarrow \frac{11}{7};\]
\[\frac{1}{5} \rightarrow 5;\]
\[8\frac{13}{15} = \frac{133}{15} \rightarrow \frac{15}{133}.\]