Answer
$\color{blue}{x^3y^8}$
Work Step by Step
RECALL:
(1) $a^m \cdot a^n = a^{m+n}$
(2) $\dfrac{a^m}{a^n} = a^{m-n}$
(3) $a^{1/n} = \sqrt[n]{a}$
(4) When $n$ is odd, $\sqrt[n]{a^n}=a$
(5) $a^{m/n} = \left(\sqrt[n]{a}\right)^m$
(6) $(ab)^m=a^mb^m$
(7) $(a^m)^n=a^{mn}$
Use rule (6) above to obtain:
$=\dfrac{(x^{1/4})^{20}(y^{2/5})^{20}}{x^2}$
Use rule (7) above to obtain:
$=\dfrac{x^{(1/4) \cdot 20}y^{(2/5) \cdot 20}}{x^2}
\\=\dfrac{x^5y^8}{x^2}$
Use rule (2) above to obtain:
$=x^{5-2}y^8
\\=\color{blue}{x^3y^8}$