Answer: [tex]\frac{x^8}{256y^{20}}[/tex]
If the font is too small, it says x^8 all over top 256y^20 as one big fraction.
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Work Shown:
[tex]\left(\frac{5x^3}{20xy^5}\right)^4\\\\\\\left(\frac{x^2}{4y^5}\right)^4\\\\\\\frac{\left(x^2\right)^4}{(4^1)^4\left(y^5\right)^4}\\\\\\\frac{x^{2*4}}{4^{1*4}y^{5*4}}\\\\\\\frac{x^{8}}{4^{4}y^{20}}\\\\\\\frac{x^{8}}{256y^{20}}\\\\\\[/tex]
