Сократите дробь: (a^7+a^13)/(a^-3+a^3).

\[\frac{a^{7} + a^{13}}{a^{- 3} + a^{3}} = \frac{a^{7}\left( 1 + a^{6} \right)}{\frac{1}{a^{3}} + a^{3}} =\]

\[= \frac{a^{7}\left( 1 + a^{6} \right)}{\frac{1 + a^{6}}{a^{3}}} =\]

\[= \frac{a^{7}\left( 1 + a^{6} \right) \cdot a³}{1 + a^{6}} = a^{10}\]