Ta có : \(x\sqrt{x}-y\sqrt{y}\)
= \(\sqrt{x}^2\sqrt{x}-\sqrt{y}^2\sqrt{y}\)
= \(\sqrt{x}^3-\sqrt{y}^3\)
= \(\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{x}^2+2\sqrt{xy}+\sqrt{y}^2\right)\)
= \(\left(\sqrt{x}-\sqrt{y}\right)\left(x+2\sqrt{xy}+y\right)\)