\[\left( \frac{a^{12}b^{- 4}}{c^{5}d^{- 13}} \right)^{- 2} = \frac{a^{- 22}b^{8}}{c^{- 10}d^{26}} = \frac{b^{8}c^{10}}{a^{22}d^{26}}.\]