Mấy bạn giúp mình với nhé
1. Rút gọn các biểu thức sau
a. \(\frac{1}{1+\sqrt{2}}+\frac{1}{\sqrt{2}+\sqrt{3}}+\frac{1}{\sqrt{3}+\sqrt{4}}+......+\frac{1}{\sqrt{2004}+\sqrt{2005}}\)
b. \(\frac{\sqrt{2+\sqrt{3}}}{2.\left(\sqrt{2}+\sqrt{6}\right)}\) c. \(\sqrt{2-\sqrt{3}}.\left(\sqrt{6}+\sqrt{2}\right)\) d. \(\sqrt{5-\sqrt{3}}-\sqrt{5+\sqrt{3}}\)
e. \(\sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}}\) f. \(\sqrt{5+\sqrt{21}}.\left(\sqrt{6}-\sqrt{14}\right)\)
g.\(\sqrt{3-\sqrt{5}}.\left(3+\sqrt{5}\right).\left(\sqrt{10}+\sqrt{2}\right)\) h. \(\frac{\sqrt{3+\sqrt{5}}.\left(\sqrt{5}-1\right)}{2\sqrt{2}}\)
i. \(\sqrt{5-\sqrt{3-\sqrt{29-6\sqrt{20}}}}\) k. \(\sqrt{\sqrt{5}-\sqrt{3-\sqrt{9-12\sqrt{5}}}}\)