Hãy tính: \(\frac{x}{y}\sqrt {\frac{{{x^2}}}{{{y^4}}}} \left( {x > 0,y \ne 0} \right)\).

* Hướng dẫn giải

 \(\begin{array}{l} \frac{x}{y}\sqrt {\frac{{{x^2}}}{{{y^4}}}} \left( {x > 0,y \ne 0} \right)\\ = \frac{x}{y}.\frac{{\sqrt {{x^2}} }}{{\sqrt {{y^4}} }} = \frac{x}{y}.\frac{{\left| x \right|}}{{{y^2}}}\\ = \frac{x}{y}.\frac{x}{{{y^2}}} = \frac{{{x^2}}}{{{y^3}}} \end{array}\)