\[\ \left( \frac{3a^{- 4}}{2b^{- 3}} \right)^{- 2} \cdot 10a^{7}b³ = \left( \frac{2b^{- 3}}{3a^{- 4}} \right)^{2} \cdot 10a^{7}b^{3} =\]
\[= \frac{4b^{- 6}}{9a^{- 8}} \cdot 10a^{7}b³ =\]
\[= \frac{4}{b^{6}}\ :\frac{9}{a^{8}} \cdot 10a^{7}b³ = \frac{4 \cdot a^{8} \cdot 10a^{7}b³}{b^{6} \cdot 9} = \frac{40a^{15}}{9b^{3}}\ \]
\[\frac{2^{- 6} \cdot 4^{- 3}}{8^{- 7}} = \frac{2^{- 6} \cdot \left( 2^{2} \right)^{- 3}}{\left( 2^{3} \right)^{- 7}} = \frac{2^{- 6} \cdot 2^{- 6}}{2^{- 21}} =\]
\[= \frac{2^{- 12}}{2^{- 21}} = 2^{9} = 512.\]
\[\left( 3,5 \cdot 10^{- 5} \right) \cdot \left( 6,4 \cdot 10^{2} \right) = 22,4 \cdot 10^{- 3} =\]
\[= 2,24 \cdot 10^{- 2}.\]
\[\left( x^{- 1} - y^{- 1} \right)(x - y)^{- 1} = \left( \frac{1}{x} - \frac{1}{y} \right) \cdot \frac{1}{x - y} =\]
\[= \frac{y - x}{\text{xy}} \cdot \frac{1}{x - y} =\]
\[= - \frac{(x - y)}{\text{xy}} \cdot \frac{1}{x - y} = - \frac{1}{\text{xy}}\]
\[\ 6^{15} \cdot 6^{- 13} = 6² = 36\]