Question

Tính: \(\frac{2\sqrt{15}-2\sqrt{10}+\sqrt{6}-3}{2\sqrt{5}-2\sqrt{10}-\sqrt{3}+\sqrt{6}}\)

Answer 1

sao gặp toàn bài lp 9 z ????

Answer 2

\(=\frac{2\sqrt{5\cdot3}-2\sqrt{5\cdot2}+\sqrt{2\cdot3}-\sqrt{3\cdot3}}{2\sqrt{5}-2\sqrt{2\cdot5}-\sqrt{3}+\sqrt{2\cdot3}}=\frac{2\sqrt{5}\left(\sqrt{3}-\sqrt{2}\right)+\sqrt{3}\left(\sqrt{2}-\sqrt{3}\right)}{2\sqrt{5}\left(1-\sqrt{2}\right)-\sqrt{3}\left(1-\sqrt{2}\right)}\)
\(=\frac{\left(\sqrt{3}-\sqrt{2}\right)\cdot\left(2\sqrt{5}-\sqrt{3}\right)}{-\left(\sqrt{2}-1\right)\cdot\left(2\sqrt{5}-\sqrt{3}\right)}=\frac{\sqrt{3}-\sqrt{2}}{1-\sqrt{2}}\)