\(=\dfrac{\sqrt{\left(\sqrt{5}-1\right)^2}}{2-2\sqrt{5}}=\dfrac{\left|\sqrt{5}-1\right|}{-2\left(\sqrt{5}-1\right)}=\dfrac{\sqrt{5}-1}{-2\left(\sqrt{5}-1\right)}=-\dfrac{1}{2}\)
Rút gọn biểu thức
a) \(\dfrac{\sqrt{14-6\sqrt{5}}}{\sqrt{5}-3}\)
b)\(\dfrac{\sqrt{3+\sqrt{5}}}{\sqrt{2}}\)
c)\(\dfrac{2+\sqrt{2}}{\sqrt{1,5+\sqrt{2}}}\)
d) \(\dfrac{\sqrt{20}}{\sqrt{5}}+\dfrac{\sqrt{117}}{\sqrt{13}}+\dfrac{\sqrt{272}}{\sqrt{17}}+\dfrac{\sqrt{105}}{\sqrt{2\dfrac{1}{7}}}\)
e)\(\dfrac{x\sqrt{x}-y\sqrt{y}}{x+\sqrt{xy}+y},x,y>0\)
f)\(\dfrac{2+\sqrt{3}}{\sqrt{2}+\sqrt{2+\sqrt{3}}}+\dfrac{2-\sqrt{3}}{\sqrt{2}-\sqrt{2-\sqrt{3}}}\)
g)\(\sqrt{\dfrac{2+a-2\sqrt{2a}}{a+3-2\sqrt{3a}}}v\text{ới}a>0,a\ne3\)
a,\(\left(\sqrt{2}+2\right)\sqrt{2}-2\sqrt{2}\)
b, \(\sqrt{(\sqrt{5}-\sqrt{10})^2}-\sqrt{10(\sqrt{2+1)}^2}\)
c,\((\sqrt{2}+\sqrt{3})^2.\sqrt{49-20\sqrt{6}}\)
d, \(\dfrac{2}{\sqrt{8-\sqrt{60}}}-\sqrt{\dfrac{\sqrt{18}+\sqrt{27}}{\sqrt{3}+\sqrt{2}}}\)
Rút gọn
a.\(\dfrac{\sqrt{7}-5}{2}-\dfrac{6}{\sqrt{7}-2}+\dfrac{1}{3+\sqrt{7}}+\dfrac{3}{5+2\sqrt{7}}\)
b.\(\left(\sqrt{10}+\sqrt{2}\right).\left(6-2\sqrt{5}\right).\sqrt{3+\sqrt{5}}\)
\(\dfrac{1}{2}\sqrt{108}-10\sqrt{\dfrac{1}{5}}-\sqrt{147}+\sqrt{20}\)
Tính:
\(\left(\dfrac{3\sqrt{3}-2\sqrt{2}}{\sqrt{3}-\sqrt{2}}+\dfrac{3\sqrt{2}+2\sqrt{3}}{\sqrt{3}+\sqrt{2}}\right)\cdot\dfrac{5-2\sqrt{6}}{4}\)
a,\(\sqrt{22+12\sqrt{2}}\)
b,\(\sqrt{\dfrac{5+2\sqrt{6}}{2}}\)
c,\(\sqrt{30+4\sqrt{2}\sqrt{7}}\)
d,\(\sqrt{5+2\sqrt{2-\sqrt{9-4\sqrt{2}}}}\)
e,\(\sqrt{1+2\sqrt{\sqrt{2+\sqrt{11+6\sqrt{2}}}}}\)
f,\(\sqrt{1+\dfrac{\sqrt{3}}{2}+\sqrt{1-\dfrac{\sqrt{3}}{2}}}\)
g,\(\sqrt{10-2\sqrt{21}}+\sqrt{4+2\sqrt{3}}\)
Bài 1 :
a, \(\dfrac{1}{2}\sqrt{12}+\sqrt{27}-\sqrt{75}\)
b, \(\sqrt{7-4\sqrt{3}}-\sqrt{4+2\sqrt{3}}\)
c, 6\(\sqrt{27}-2\sqrt{75}-\dfrac{1}{2}\sqrt{300}\)
d, \(\dfrac{7}{\sqrt{10}-\sqrt{3}}-\dfrac{5\sqrt{2}-2\sqrt{5}}{\sqrt{5}-\sqrt{2}}-\dfrac{6}{\sqrt{3}}\)
e, \(\sqrt{\dfrac{\sqrt{5}}{8\sqrt{5}+3\sqrt{35}}}.(3\sqrt{2}+\sqrt{14)}\)
f, \(\sqrt{11-4\sqrt{ }7}+\dfrac{2\sqrt{7}-2}{\sqrt{7}-1}\)
g, \((\sqrt{125}-3\sqrt{3})\dfrac{\sqrt{5}-\sqrt{3}}{8+\sqrt{15}}\)
h, \(\sqrt{100}-\sqrt{64}\)
i, \(\sqrt{(1-\sqrt{3})^2}-\sqrt{3}\)
Bạn nào biết làm bài này thì giúp mình với ạ ! sáng mai mình cần gấp !
\(a,2\sqrt{20}-\sqrt{50}+3\sqrt{80}-\sqrt{320}\)
\(b,\sqrt{32}-\sqrt{50}+\sqrt{18}\)
\(c,3\sqrt{3}+4\sqrt{2}-5\sqrt{27}\)
\(d,\dfrac{\sqrt{3}}{\sqrt{\sqrt{3}+1}-1}-\dfrac{\sqrt{3}}{\sqrt{\sqrt{3}+1}+1}\)
e,\(\left(2+\dfrac{3+\sqrt{3}}{\sqrt{3}+1}\right)\left(2-\dfrac{3-\sqrt{3}}{\sqrt{3}-1}\right)\)
Tính GT của biểu thức
D = \(\left(6\sqrt{\dfrac{8}{9}}-5\sqrt{\dfrac{32}{45}}+3\sqrt{\dfrac{18}{49}}\right).\sqrt{\dfrac{1}{2}}\)
