Rút gọn biểu thức sau :
a)\(\frac{2}{\sqrt{7}-5}-\frac{2}{\sqrt{7}+5}\)
b)\(\frac{\sqrt{7}+\sqrt{5}}{\sqrt{7}-\sqrt{5}}+\frac{\sqrt{7}-\sqrt{5}}{\sqrt{7}+\sqrt{5}}\)
c)\(\left(\frac{\sqrt{14}-\sqrt{7}}{1-\sqrt{2}}+\frac{\sqrt{15}-\sqrt{5}}{1-\sqrt{3}}\right)\frac{1}{\sqrt{7}-\sqrt{5}}\)
d)\(\frac{3}{\sqrt{5}-2}+\frac{2}{\sqrt{5}+3}-\frac{1}{\sqrt{5}+4}\)
giúp mình với ạ
rút gọn
a) \(\frac{7\sqrt{2}+2\sqrt{7}}{\sqrt{14}}-\frac{5}{\sqrt{7}+\sqrt{5}}\)
b) \(\frac{\sqrt{2}\left(3+\sqrt{5}\right)}{2\sqrt{2}+\sqrt{3+\sqrt{5}}}+\frac{\sqrt{2}\left(3-\sqrt{5}\right)}{2\sqrt{2}-\sqrt{3-\sqrt{5}}}\)
c) \(\sqrt[3]{16-8\sqrt{5}}+\sqrt[3]{16\text{ }+8\sqrt{5}}\)
helppp mee
Rút gọn \(\frac{5}{4-\sqrt{11}}+\frac{1}{3+\sqrt{7}}-\frac{6}{\sqrt{7}-2}-\frac{\sqrt{7}-5}{2}\)
Rút gọn các biểu thức sau:
1) \(\frac{1}{\sqrt{7-\sqrt{24}+1}}-\frac{1}{\sqrt{7+\sqrt{24}}}\)
2) \(\frac{\sqrt{3}}{\sqrt{\sqrt{3}+1}-1}-\frac{\sqrt{3}}{\sqrt{\sqrt{3}-1}+1}\)
3) \(\sqrt{\frac{5+2\sqrt{6}}{5-\sqrt{6}}}+\sqrt{\frac{5-2\sqrt{6}}{5+\sqrt{6}}}\)
4) \(\sqrt{\frac{3+\sqrt{5}}{3-\sqrt{5}}}+\sqrt{\frac{3-\sqrt{5}}{3+\sqrt{5}}}\)
1,Rút gọn:
a, \(\frac{1}{\sqrt{2}+1}+\frac{1}{\sqrt{3}+\sqrt{2}}+\frac{1}{\sqrt{4}+2}\)
b,\(\frac{1}{\sqrt{1}-\sqrt{2}}-\frac{1}{\sqrt{2}-\sqrt{3}}+\frac{1}{\sqrt{3}-\sqrt{4}}-\frac{1}{\sqrt{4}-\sqrt{5}}+\frac{1}{\sqrt{5}-\sqrt{6}}-\frac{1}{\sqrt{6}-\sqrt{7}}+\frac{1}{\sqrt{7}-\sqrt{8}}-\frac{1}{\sqrt{8}-\sqrt{9}}\)
Rút gọn biểu thức: \(A=\dfrac{\sqrt{3+\sqrt{5}}}{\sqrt{2}-\sqrt{3-\sqrt{5}}}-\dfrac{\sqrt{3-\sqrt{5}}}{\sqrt{2}+\sqrt{3+\sqrt{5}}}\)
rút gọn
\(\dfrac{2\sqrt{x}}{\sqrt{x}+3}+\dfrac{\sqrt{x}+1}{\sqrt{x}-3}+\dfrac{7\sqrt{x}+3}{9-x}\)
Rút gọn: \(\sqrt{6+2\sqrt{5}}+\sqrt{\frac{2}{7+3\sqrt{5}}}\)
Rút gọn biểu thức :
a) \(A=\sqrt{4+\sqrt{7}}+\sqrt{4-\sqrt{7}}\)
b) \(B=\frac{2+\sqrt{6}+\sqrt{10}+\sqrt{2}+\sqrt{3}+\sqrt{5}}{\sqrt{8}+\sqrt{12}+\sqrt{20}}.\frac{\sqrt{2}-1}{3}\)
