a)\(\sqrt{6-2\sqrt{5}}-\sqrt{6+2\sqrt{5}}\)
b) \(\sqrt{7+4\sqrt{3}}-\sqrt{4+2\sqrt{3}}\)
c) \(\sqrt{8+2\sqrt{7}}+\sqrt{8-2\sqrt{7}}\)
d)\(\sqrt{7+2\sqrt{10}}-\sqrt{3-2\sqrt{2}}\)
\(A=\left(3+\sqrt{5}\right).\left(\sqrt{10}-\sqrt{2}\right)\sqrt{3}-\sqrt{5}\)
B=\(B=\left(\sqrt{10}+\sqrt{6}\right)\sqrt{8}-2\sqrt{15}\)
\(Cho\sqrt{8-a}+\sqrt{5+a}=5tinh\sqrt{\left(8-a\right)\left(5+a\right)}\)
Tính
1) \(\sqrt{18}.\sqrt{2}\)
2) \(\sqrt{15^2-9^2}\)
3) \(\sqrt{46-6\sqrt{5}}-\sqrt{46+6\sqrt{5}}\)
4)\(\sqrt{21+6\sqrt{6}}-\sqrt{21-6\sqrt{6}}\)
5) \(\left(2+\sqrt{5}\right).\sqrt{9-4\sqrt{5}}\)
6)\(\left(3-\sqrt{2}\right).\sqrt{7+4\sqrt{3}}\)
7)\(\left(\sqrt{3}+\sqrt{5}\right).\sqrt{7-2\sqrt{10}}\)
8)\(\left(\sqrt{6}+\sqrt{10}\right).\sqrt{4-\sqrt{15}}\)
9) \(\sqrt{2}.\left(\sqrt{8}-\sqrt{32}+3\sqrt{18}\right)\)
10) \(\sqrt{2}\left(\sqrt{2}-\sqrt{3-\sqrt{5}}\right)\)
11) \(\sqrt{3}-\sqrt{2}-\sqrt{\left(\sqrt{3}+\sqrt{2}\right)^2}\)
12) \(\left(\sqrt{2}-\sqrt{3+\sqrt{5}}\right).\sqrt{2}+2\sqrt{5}\)
1)Tính:
a)(\(\sqrt{3-\sqrt{5}}+\sqrt{3+\sqrt{5}}\))\(^2\) b)\(\sqrt{2-\sqrt{3}-\sqrt{2+\sqrt{3}}}\) c)\(\frac{\sqrt{10}+\sqrt{6}}{2\sqrt{5}+\sqrt{12}}\) d)\(\sqrt{8-2\sqrt{15}-\sqrt{8+2\sqrt{15}}}\) e)\(\sqrt{\left(1-\sqrt{2007}\right)^2}.\sqrt{2008+2\sqrt{2007}}\)
b1. Rút gọn
a)\(\frac{5\sqrt{6}+6\sqrt{5}}{\sqrt{5}+\sqrt{6}}\)
b) \(\frac{2\sqrt{7}-4\sqrt{3}}{3\sqrt{35}-6\sqrt{15}}\)
c) \(\frac{12\sqrt{10}-16\sqrt{14}}{6\sqrt{5}-8\sqrt{7}}\)
d) \(\frac{6\sqrt{6}-27}{2\sqrt{2}-3\sqrt{3}}\)
e) \(\frac{-4\sqrt{2}+3\sqrt{5}}{-2\sqrt{10}}\)
\(2\sqrt{10}.5\sqrt{8}.\sqrt{2}\)
Tính
\(\sqrt{20}.\left(5\sqrt{3}+\sqrt{5}\right)\)
\(\left(3\sqrt{2}+\sqrt{3}\right)^2\)
A)\(\sqrt{2-\sqrt{3}}.\left(\sqrt{6}+\sqrt{2}\right)\)
B)\(\left(\sqrt{2}+1^{ }\right)^3-\left(\sqrt{2}-1\right)^3\) C)\(\dfrac{2\sqrt{8}-\sqrt{12}}{\sqrt{18}-\sqrt{48}}-\dfrac{\sqrt{5}+\sqrt{27}}{\sqrt{30}+\sqrt{162}}\) D)\(\sqrt{\dfrac{2-\sqrt{3}}{2+\sqrt{3}}}+\sqrt{\dfrac{2+\sqrt{3}}{2-\sqrt{3}}}\) E)\(\dfrac{\sqrt{3-\sqrt{5}}.\left(3+\sqrt{5}\right)}{\sqrt{10}+\sqrt{2}}\) F)\(\dfrac{1}{\sqrt{2}+\sqrt{2+\sqrt{3}}}+\dfrac{1}{\sqrt{2}-\sqrt{2-\sqrt{3}}}\)
Bài 1 : Rút gọn biểu thức sau :
\(\frac{\sqrt{2}+\sqrt{3}+\sqrt{6}+\sqrt{8}+\sqrt{16}}{\sqrt{2}+\sqrt{3}+\sqrt{4}}\)
Bài 2 : Chứng minh đẳng thức sau :
\(\sqrt{8+2\sqrt{10+2\sqrt{5}}}.\sqrt{8-2\sqrt{10+2\sqrt{5}}}=2\sqrt{5}-2\)
Bài 3 : Cho biểu thức E = \(\left(\frac{\sqrt{x}+1}{\sqrt{x}-1}-\frac{\sqrt{x}-1}{\sqrt{x}+1}+4\sqrt{x}\right):\left(\sqrt{x}-\frac{1}{\sqrt{x}}\right)\)
a) Rút gọn biẻu thức E
b) Tính giá trị của E khi x = \(\left(4+\sqrt{15}\right)\left(\sqrt{10}-\sqrt{6}\right)\sqrt{4-\sqrt{15}}\)
Rút gọn:
A = \(\sqrt{2}\left(\sqrt{8}-\sqrt{32}-2\sqrt{18}\right)\)
B = \(\left(\sqrt{2}-\sqrt{3-\sqrt{5}}\right)\)
C = \(\sqrt{4-\sqrt{7}}-\sqrt{4+\sqrt{7}}\)
D = \(\sqrt{3}-\sqrt{2}-\sqrt{\sqrt{3}+\sqrt{2}}\)
E = \(\left(\sqrt{2}-\sqrt{3}+\sqrt{5}\right)\sqrt{2}+2\sqrt{5}\)
F = \(\left(\sqrt{14}-\sqrt{10}\right)\left(\sqrt{6+\sqrt{35}}\right)\)
G = \(\sqrt{11-4\sqrt{7}}-\sqrt{2}\times\sqrt{8+3\sqrt{7}}\)