\[\frac{15^{7} \cdot 3^{- 12}}{45^{- 4} \cdot 5^{13}} = \frac{(3 \cdot 5)^{7} \cdot 3^{- 12}}{\left( 3^{2} \cdot 5 \right)^{- 4} \cdot 5^{13}} =\]
\[= \frac{3^{7} \cdot 5^{7} \cdot 3^{- 12}}{3^{- 8} \cdot 5^{- 4} \cdot 5^{13}} = \frac{3^{- 5} \cdot 5^{7}}{3^{- 8} \cdot 5^{9}} =\]
\[= \frac{3^{3}}{5^{2}} = \frac{27}{25} = 1\frac{2}{25}\]