a) Ta có: \(A=\dfrac{1}{\sqrt{3}-\sqrt{2}}+\dfrac{1}{\sqrt{3}+\sqrt{2}}\)
\(=\sqrt{3}+\sqrt{2}+\sqrt{3}-\sqrt{2}\)
\(=2\sqrt{3}\)
b) Ta có: \(B=\dfrac{x\sqrt{y}-y\sqrt{x}}{\sqrt{xy}}+\dfrac{x-y}{\sqrt{x}-\sqrt{y}}\)
\(=\dfrac{\sqrt{xy}\left(\sqrt{x}-\sqrt{y}\right)}{\sqrt{xy}}+\dfrac{\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{x}+\sqrt{y}\right)}{\sqrt{x}-\sqrt{y}}\)
\(=\sqrt{x}-\sqrt{y}+\sqrt{x}+\sqrt{y}\)
\(=2\sqrt{x}\)
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