\(\frac{7+\sqrt{7}}{1+\sqrt{7}}+\frac{7-\sqrt{7}}{1-\sqrt{7}}=\frac{\sqrt{7}\left(1+\sqrt{7}\right)}{1+\sqrt{7}}+\frac{\sqrt{7}\left(1-\sqrt{7}\right)}{1-\sqrt{7}}=\sqrt{7}+\sqrt{7}=2\sqrt{7}\)
Thu gọn biểu thức:
D= \(\left(\frac{\sqrt{7}-7}{1-\sqrt{7}}-\frac{\sqrt{7}+1}{7+\sqrt{7}}\right):\frac{\sqrt{7}+1}{\sqrt{7}}-7\sqrt{\frac{1}{\sqrt{7}}}\)
Tính:
a) \(A=\sqrt{8-2\sqrt{15}}\left(\sqrt{3}+\sqrt{5}\right)-\left(\sqrt{45}-\sqrt{20}\right)\)
b) \(B=\left(\frac{\sqrt{21}-\sqrt{3}}{\sqrt{7}-1}-\frac{\sqrt{15}-\sqrt{3}}{1-\sqrt{5}}\right)\left(\frac{1}{2}\sqrt{6}-\sqrt{\frac{3}{2}}+3\sqrt{\frac{2}{3}}\right)\)
c) \(C=2\sqrt{3}+\sqrt{7-4\sqrt{3}}+\left(\sqrt{\frac{1}{3}}-\sqrt{\frac{4}{3}+}\sqrt{3}\right):\sqrt{3}\)
d) \(D=\left(\frac{5+\sqrt{5}}{5-\sqrt{5}}+\frac{5-\sqrt{5}}{5+\sqrt{5}}\right):\frac{1}{\sqrt{7-4\sqrt{3}}}\)
Rút gọn biểu thức: \(D=\frac{\sqrt{\sqrt{7}-\sqrt{3}}-\sqrt{\sqrt{7}+\sqrt{3}}}{\sqrt{\sqrt{7}-2}}\)
\(8\sqrt{\frac{2}{5}}+7\sqrt{\frac{5}{2}}-\frac{\sqrt{33}}{\sqrt{3}}+\frac{10}{\sqrt{11}-1}\)
Rút gọn biểu thức:
\(\frac{\sqrt{7+\sqrt{5}}+\sqrt{7-\sqrt{5}}}{\sqrt{7+2\sqrt{11}}}-\sqrt{3-2\sqrt{2}}\)
Rút gọn biểu thức:
a) \(A=\sqrt{7-4\sqrt{3}}-\sqrt{7+4\sqrt{3}}\)
b) \(B=\left(\frac{\sqrt{x}+1}{x-4}-\frac{\sqrt{x}-1}{x+4\sqrt{x}+4}\right).\frac{x\sqrt{x}+2x-4\sqrt{x}-8}{\sqrt{x}}\) với \(x>0,x\ne4\)
Tính :
A=\(\frac{\sqrt{\sqrt{7}-\sqrt{3}}-\sqrt{\sqrt{7}+\sqrt{3}}}{\sqrt{\sqrt{7}}-2}\)
B= \(\sqrt{6+2\sqrt{2}-\sqrt{3}-\sqrt{4+2\sqrt{3}}}\)
rút gọn biểu thức
a, \(\dfrac{1}{\sqrt{7-\sqrt{24}+1}}-\dfrac{1}{\sqrt{7+\sqrt{24}+1}}\)
b,\(\sqrt{\dfrac{3+\sqrt{5}}{3-\sqrt{5}}}+\sqrt{\dfrac{3-\sqrt{5}}{3+\sqrt{5}}}\)
c,\(\dfrac{4+\sqrt{7}}{3\sqrt{2}+\sqrt{4}+\sqrt{7}}+\dfrac{4-\sqrt{7}}{3\sqrt{7}-\sqrt{4}-\sqrt{7}}\)
\(\frac{2}{3-\sqrt{7}}+\frac{2}{\sqrt{7}-2}\)
