Question

Rút gọn

Answer 1

\(\dfrac{\sqrt{5}-\sqrt{2}}{\sqrt{5}+\sqrt{2}}-\dfrac{\sqrt{5}+\sqrt{2}}{\sqrt{5}-\sqrt{2}}-\dfrac{2}{\sqrt{10}}\)

\(=\dfrac{7-2\sqrt{10}}{3}-\dfrac{\sqrt{5}+\sqrt{2}}{\sqrt{5}-\sqrt{2}}-\dfrac{2}{\sqrt{10}}\)\(=\dfrac{7-2\sqrt{10}}{3}-\dfrac{7+2\sqrt{10}}{3}-\dfrac{2}{\sqrt{10}}\)

\(=\dfrac{7-2\sqrt{10}}{3}-\dfrac{7+2\sqrt{10}}{3}-\dfrac{\sqrt{2}}{\sqrt{5}}=-\dfrac{4\sqrt{10}}{3}-\dfrac{\sqrt{2}}{\sqrt{5}}.\)