\(\frac{\sqrt{10}}{2}=\sqrt{\frac{10}{4}}-2\sqrt{5}\)
\(\frac{-\sqrt{10}}{2}=\frac{-\sqrt{2.5}}{2}=\frac{-\sqrt{2}.\sqrt{5}}{2}=-\frac{\sqrt{5}}{\sqrt{2}}=-\sqrt{\frac{5}{2}}>-2\sqrt{5}\)
đúng k
\(\frac{\sqrt{10}}{2}=\sqrt{\frac{10}{4}}-2\sqrt{5}\)
\(\frac{-\sqrt{10}}{2}=\frac{-\sqrt{2.5}}{2}=\frac{-\sqrt{2}.\sqrt{5}}{2}=-\frac{\sqrt{5}}{\sqrt{2}}=-\sqrt{\frac{5}{2}}>-2\sqrt{5}\)
đúng k
\(sosanh\frac{\sqrt{8}}{3}va\frac{3}{4}\)
So sánh:
1,\(2-\sqrt{2}va\frac{1}{2}\)
2, \(2\sqrt{3}-5va\sqrt{3}-4\)
3, \(\sqrt{3}-3\sqrt{2}va-4\sqrt{3}+5\sqrt{2}\)
4,\(1-\sqrt{3}va\sqrt{2}-\sqrt{6}\)
5, \(\sqrt{4\sqrt{5}}va\sqrt{5\sqrt{3}}\)
6, \(\sqrt{\sqrt{6}-\sqrt{5}}-\sqrt{\sqrt{3}-\sqrt{2}}va..0\)
7, \(-2\sqrt{\frac{1}{2}\sqrt{5}}va-3\sqrt{\frac{1}{3}\sqrt{2}}\)
a) Rút gọn biểu thức:
\(P=\frac{5+\sqrt{10}+\sqrt{17}}{2}\left(\frac{5+\sqrt{10}+\sqrt{17}}{2}-5\right)\left(\frac{5+\sqrt{10}+\sqrt{17}}{2}-\sqrt{10}\right)\left(\frac{5+\sqrt{10}+\sqrt{17}}{2}-\sqrt{17}\right).\)
b) Giải phương trình: \(\frac{x+2}{2x-1}+|\frac{4x-2}{x+2}|+1=0\)
Thực hiện phép tính:
a)\(\frac{10+2\sqrt{10}}{\sqrt{5}+\sqrt{2}}+\frac{8}{1-\sqrt{5}}\)
b) \(\frac{2\sqrt{8}-\sqrt{12}}{\sqrt{18}-\sqrt{48}}-\frac{\sqrt{5}+\sqrt{27}}{\sqrt{30}+\sqrt{162}}\)
c) \(\sqrt{\frac{2-\sqrt{3}}{2+\sqrt{3}}}+\sqrt{\frac{2+\sqrt{3}}{2-\sqrt{3}}}\)
d)\(\frac{\left(\sqrt{5}+2\right)^2-8\sqrt{5}}{2\sqrt{5}-4}\)
Rút Gọn A=\(\frac{\left(\frac{1}{4}-\frac{\sqrt{2}}{7}+\frac{3\sqrt{2}}{35}\right)\frac{1}{25}}{\left(\frac{1}{10}+\frac{3\sqrt{2}}{35}-\frac{\sqrt{2}}{5}\right)\frac{5}{7}}\)
B=\(\frac{3+\sqrt{5}}{\sqrt{10}+\sqrt{3+\sqrt{5}}}-\frac{3-\sqrt{5}}{\sqrt{10}+\sqrt{3+\sqrt{5}}}\)
C=\(\frac{3+\sqrt{5}}{\sqrt{2}+\sqrt{3+\sqrt{5}}}-\frac{3-\sqrt{5}}{\sqrt{2}-\sqrt{3-\sqrt{5}}}\)
\(2\sqrt{4+2\sqrt{3}}+\sqrt{5+2\sqrt{6}}-\sqrt{30-2\sqrt{2}+6\sqrt{3}\cdot\left(1-\sqrt{2}\right)}\)
\(\frac{3+\sqrt{5}}{\sqrt{10}+\sqrt{3+\sqrt{5}}}-\frac{3-\sqrt{5}}{\sqrt{10}+\sqrt{3-\sqrt{5}}}\)
CM A thuoc Z va B thuoc Z voi :
A = \(\sqrt{6-2\sqrt{5}}-\sqrt{6+2\sqrt{5}}\)
B = \(\frac{\sqrt{3-2\sqrt{2}}}{\sqrt{17-12\sqrt{2}}}-\frac{\sqrt{3+2\sqrt{2}}}{\sqrt{17+12\sqrt{2}}}\)
\(\frac{6}{\sqrt{7}+2}+\sqrt{\frac{2}{8+3\sqrt{7}}}\)
\(\frac{8+2\sqrt{2}}{3-\sqrt{2}}-\frac{2+3\sqrt{2}}{\sqrt{2}}+\frac{\sqrt{2}}{1-\sqrt{2}}\)
C=\(\sqrt{4+\sqrt{10+2\sqrt{5}}}+\sqrt{4+\sqrt{10-2\sqrt{5}}}\)
Tính :
a, \(B=\sqrt{3-\sqrt{5}}\left(\sqrt{10}-\sqrt{2}\right)\left(3+\sqrt{5}\right)\)
b, \(A=\sqrt{4+\sqrt{10+2\sqrt{5}}}+\sqrt{4-\sqrt{10+2\sqrt{5}}}\)
c, \(C=\frac{1}{\sqrt{3}}+\frac{1}{3\sqrt{2}}-\frac{\sqrt{5-2\sqrt{6}}}{3}\)