\(\sqrt{x^2y}\sqrt{x^3y^3}:\sqrt{\dfrac{x}{y}}=\left|x\right|\sqrt{y}\sqrt{x^3y^3}:\dfrac{\sqrt{x}}{\sqrt{y}}\)
\(=\left|x\right|\sqrt{y}\sqrt{x^3y^3}.\dfrac{\sqrt{y}}{\sqrt{x}}\)
\(=\dfrac{\left|xy\right|\sqrt{x^3y^3}}{\sqrt{x}}\)
\(\sqrt{x^2y}\sqrt{x^3y^3}:\sqrt{\dfrac{x}{y}}\\ =x\sqrt{y}.xy\sqrt{xy}.\dfrac{\sqrt{y}}{\sqrt{x}}\\ =\dfrac{x\sqrt{y}.xy\sqrt{x}.\sqrt[]{y}.\sqrt{y}}{\sqrt{x}}\\ =x\sqrt{y}.xy.y=x\sqrt{y}.xy^2\)