~fractions
[tex] \large \tt( \frac{ 5 }{ 7 } ) ^ { 3 } ( \frac{ 4 }{ 5 } ) ^ { 3 }[/tex]
[tex] \large \tt = \frac{125}{343}\times \left(\frac{64}{125}\right) [/tex]
[tex] \large \tt = \frac{125\times 64}{343\times 125} [/tex]
[tex] \large \tt = \boxed{\frac{64}{343} } \: ✓[/tex]
~ nice to help you ^^
