Answer
$\left( 5x-4\right) \left( 25x^{2}-10x+4\right) $
Work Step by Step
$\left( 5x-2\right) ^{3}-8=\left( 5x-2\right) ^{3}-2^{3}=\left( 5x-2-2\right) \left( \left( 5x-2\right) ^{2}+2\times \left( 5x-2\right) +2^{2}\right) =\left( 5x-4\right) \left( 25x^{2}-10x+4\right) $
