We need to prove that
[tex](\frac{4}{5})^{-3}=\frac{5^3}{4^3}^{}^{}[/tex]this will be equivalent to prove that:
[tex]4^3\times(\frac{4}{5})^{-3}=5^3[/tex]so let's start from the left side of the previous equality and try to obtain the right side:
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