( - 0,36)^3; - 25/9 với a = 3/5

Lời giải:

 \[{( - 0,36)^3}\,:\,\frac{{ - 25}}{9} = {\left( {\frac{{ - 9}}{{25}}} \right)^3}\,.\,\left( {\frac{{ - 9}}{{25}}} \right)\]

\[ = {\left( {\frac{{ - 9}}{{25}}} \right)^4} = {\left( {\frac{9}{{25}}} \right)^4} = {\left( {\frac{{{3^2}}}{{{5^2}}}} \right)^4}\]

\[ = {\left[ {{{\left( {\frac{3}{5}} \right)}^2}} \right]^4} = {\left( {\frac{3}{5}} \right)^{2\,.\,4}} = {\left( {\frac{3}{5}} \right)^8}\].