In order to solve $ \color{blue}{ 64x^{5}-80x^{3}+20x = 0 } $, first we need to factor our $ x $.
$$ 64x^{5}-80x^{3}+20x = x \left( 64x^{4}-80x^{2}+20 \right) $$$ x = 0 $ is a root of multiplicity $ 1 $.
The remaining roots can be found by solving equation $ 64x^{4}-80x^{2}+20 = 0$.
This polynomial has no rational roots that can be found using Rational Root Test.
Roots were found using quartic formulas