\(\sqrt{3-\sqrt{5}}:\sqrt{2}=\sqrt{\dfrac{3-\sqrt{5}}{2}}=\sqrt{\dfrac{2\left(3-\sqrt{5}\right)}{4}}=\sqrt{\dfrac{6-2\sqrt{5}}{4}}=\sqrt{\dfrac{5-2\sqrt{5}+1}{4}}=\sqrt{\dfrac{\left(\sqrt{5}-1\right)^2}{4}}=\dfrac{\sqrt{\left(\sqrt{5}-1\right)^2}}{\sqrt{4}}=\dfrac{\left|\sqrt{5}-1\right|}{2}=\dfrac{\sqrt{5}-1}{2}\)(vì \(\sqrt{5}-1\)>0)
1
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. \(\frac{\sqrt{3-\sqrt{5}}.\left(3+\sqrt{5}\right)}{\sqrt{10}+\sqrt{2}}\) e. \(\frac{1}{\sqrt{2}+\sqrt{2+\sqrt{3}}}+\frac{1}{\sqrt{2}-\sqrt{2-\sqrt{3}}}\) f. \(\frac{\left(\sqrt{5}+2\right)^2-8\sqrt{5}}{2\sqrt{5}-4}\)
Tính:
A=\(\sqrt{4+2\sqrt{3}}-\sqrt{4-2\sqrt{3}}\)
B=\(\sqrt{9-4\sqrt{5}}+\sqrt{9+4\sqrt{5}}\)
C=\(\sqrt{4-\sqrt{7}}-\sqrt{4+\sqrt{7}}\)
D=\(\sqrt{5\sqrt{3+5\sqrt{48-10\sqrt{7+4\sqrt{3}}}}}\)
E=\(\left(4+\sqrt{15}\right)\left(\sqrt{10}-\sqrt{6}\right)\sqrt{4-\sqrt{15}}\)(2 cách)
F=\(\dfrac{\sqrt{17-12\sqrt{2}}}{\sqrt{3-2\sqrt{2}}}-\dfrac{\sqrt{17}+12\sqrt{2}}{\sqrt{3+2\sqrt{2}}}\)
\(\sqrt{3}×\sqrt{27}-\sqrt{144}:\sqrt{36}\)
\(\left(2\sqrt{9}+3\sqrt{36}\right):4\)
\(\sqrt{7}-\sqrt{8-2\sqrt{7}}\)
\(\dfrac{\sqrt{4-2\sqrt{3}}}{\sqrt{6}-\sqrt{2}}\)
\(\dfrac{5+3\sqrt{5}}{\sqrt{5}}+\dfrac{3+\sqrt{3}}{\sqrt{3}+1}-\left(\sqrt{5}+3\right)\)
\(\sqrt{27}+5\sqrt{12}-2\sqrt{3}=11\sqrt{3}\)
Tính
a) \(\frac{10}{\sqrt{5}}+\frac{8}{3 +\sqrt{5}}-\frac{\sqrt{15}-2\sqrt{5}}{\sqrt{3}-2}\)
b) \(\left(\frac{\sqrt{14}-\sqrt{7}}{\sqrt{2}-1}-\frac{\sqrt{15}-\sqrt{5}}{1-\sqrt{3}}\right):\frac{1}{\sqrt{5}-\sqrt{7}}\)
\(C=\left(2-\sqrt{3}\right)\sqrt{26+15\sqrt{3}}-\left(2+\sqrt{3}\right)\sqrt{26-15\sqrt{3}}\)
D= \(\sqrt{3+\sqrt{5}}-\sqrt{3-\sqrt{5}}-\sqrt{2}\)
Trục căn thức ở mẫu:
B = \(\dfrac{1+\sqrt{5}}{2-\sqrt{5}}\) C = \(\dfrac{5-\sqrt{x}}{2\sqrt{x}}\)
D = \(\dfrac{\sqrt{a}+1}{2\sqrt{a}-1}\) E = \(\dfrac{15}{5\sqrt{3}-3\sqrt{5}}\)
Tính:
a) \(\dfrac{\sqrt{3-\sqrt{5}}.\left(3+\sqrt{5}\right)}{\sqrt{10}+\sqrt{2}}\)
b) \(\dfrac{1}{\sqrt{2}+\sqrt{2+\sqrt{3}}}+\dfrac{1}{\sqrt{2}-\sqrt{2-\sqrt{3}}}\)
c) \(\dfrac{\left(\sqrt{5}+2\right)^2-8\sqrt{5}}{2\sqrt{5}-4}\)
Mọi người giúp em với! Em cám ơn trước ạ.
tính
1\(\left(5\sqrt{3}+3\sqrt{5}\right):\sqrt{15}\)
2\(\left(2\sqrt{3}-3\right):5\sqrt{3}\)
3\(\left(2\sqrt{18}-3\sqrt{8}+6\right):\sqrt{2}\)
4\(\sqrt{27\left(1-\sqrt{3}\right)^2}:3\sqrt{15}\)
5\(\dfrac{a-\sqrt{b}}{\sqrt{b}}:\dfrac{\sqrt{b}}{a+\sqrt{b}}\)
tính:
a) \(\sqrt{\dfrac{1}{8}}.\sqrt{2}.\sqrt{125}.\sqrt{\dfrac{1}{5}}\)
b)\(\sqrt{\sqrt{2}-1}.\sqrt{\sqrt{2}+1}\)
c) \(\sqrt{11-6\sqrt{2}}.\sqrt{11+6\sqrt{2}}\)
d) \(\sqrt{12-6\sqrt{3}}.\sqrt{\dfrac{1}{3-\sqrt{3}}}\)
e) \(\dfrac{\sqrt{15}-\sqrt{6}}{\sqrt{35}-\sqrt{14}}\)
f) \(\dfrac{2\sqrt{15}-2\sqrt{10}+\sqrt{6}-3}{2\sqrt{5}-2\sqrt{10}-\sqrt{3}+\sqrt{6}}\)
g) \(\left(\dfrac{1}{5-2\sqrt{6}}+\dfrac{2}{5+2\sqrt{6}}\right)\left(15+2\sqrt{6}\right)\)
Tính
a.\(\sqrt{\dfrac{\left(1-\sqrt{3}\right)^2}{9}}+\dfrac{2}{4+\sqrt{4-2\sqrt{3}}}\)
b.\(\dfrac{\sqrt{\sqrt{5}+\sqrt{2}}}{\sqrt{3\sqrt{5}-3\sqrt{2}}}\)
