Answer:
[tex][( \frac{ {a}^{ - 2} }{ {b} ^{7} } ) ^{ - 3} \times ( \frac{9}{ {b}^{ - 3} } )] ^{ - 1} \\ \\ \\ \frac{1}{[( \frac{ {a}^{ - 2} }{ {b} ^{7} } ) ^{ - 3} \times ( \frac{9}{ {b}^{ - 3} } )] ^{ 1}} \\ \\ \\ \frac{1}{[ \frac{1}{(\frac{ {a}^{ - 2} }{ {b} ^{7} } ) ^{ 3}} \times ( \frac{9}{ {b}^{ - 3} } )] ^{ 1}} \\ \\ \\ \frac{1}{[ \frac{1}{(\frac{ \frac{1}{ {a}^{2} } }{ {b} ^{7} } ) ^{ 3}} \times ( \frac{9}{ \frac{1}{ {b}^{3} } } )] ^{ 1}} \\ \\ \\ \frac{1}{[(1 \div {( \frac{ \frac{1}{ {a}^{2} } }{ {b}^{7} } }) ^{3}) \times (9 \div \frac{1}{ {b}^{3} } )]} \\ \\ \\ \frac{1}{(1 \times (\frac{ {b}^{7} }{ \frac{1}{ {a}^{2} } } ) ^{3} ) \times (9 \times \frac{ {b}^{3} }{1}) } \\ \\ \\ \frac{1}{( \frac{ {b}^{7} }{ \frac{1}{ {a}^{2} } } ) ^{3} \times 9 {b}^{3} } \\ \\ \\ \frac{1}{ {( {b}^{7} \div \frac{1}{ {a}^{2} }) }^{3} \times 9 {b}^{3} } \\ \\ \\ \frac{1}{( {b}^{7} \times \frac{ {a}^{2} }{1}) ^{3} \times 9 {b}^{3} } \\ \\ \\ \frac{1}{ ({b}^{7} {a}^{2} ) ^{3} \times 9 {b}^{3} } \\ \\ \\ \frac{1}{ {b}^{21} {a}^{6} \times 9 {b}^{3} } \\ \\ \\ = \frac{1}{9 {b}^{24} {a}^{6} } [/tex]
I hope I helped you^_^
