\[\ 2,4x^{- 8}y^{5} \cdot 5x^{9}y^{- 7} = \frac{12x}{y^{2}}\ \]
\[\ \left( \frac{1}{4}x^{- 2}y^{- 3} \right)^{- 2} = \left( \frac{1}{4 \cdot x^{2}y^{3}} \right)^{- 2} =\]
\[= \left( 4x^{2}y^{3} \right)^{2} = 16x^{4}y^{6}\]