We have
[tex](x^2y)^3\sqrt[]{y^4}[/tex]we will use the next formulas in we can simplify the expression
[tex]\sqrt[m]{x^n}=x^{\frac{n}{m}}[/tex][tex](x^m)^n=x^{m\cdot n}[/tex][tex]x^m\cdot x^n=x^{m+n}[/tex]so we can simplify the expression as
[tex](x^2y)^3\sqrt[]{y^4}=x^{3\cdot2}y^{3\cdot1}(y^{\frac{4}{2}})=x^6y^3y^2=x^6y^{3+5}=x^6y^5[/tex]the expression simplified is
[tex](x^2y)^3\sqrt[]{y^4}=x^6y^5[/tex]