a: \(=\left(\sqrt{2}-\sqrt{5}\right)^2-7\)
\(=7-2\sqrt{10}-7=-2\sqrt{10}\)
b: \(=\left(\sqrt{2}+\sqrt{3}\right)^2-5=5+2\sqrt{6}-5=2\sqrt{6}\)
c: \(=5-\left(\sqrt{2}-\sqrt{3}\right)^2\)
\(=5-5+2\sqrt{6}=2\sqrt{6}\)
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) \(\left(\sqrt{2}-\sqrt{3+\sqrt{5}}\right).\sqrt{2}+2\sqrt{5}\)
tính
\(\sqrt{5}.\left(\sqrt{3}+\sqrt{2}\right)\)
\(\left(\sqrt{3}-\sqrt{5}\right)^2\)
\(\left(\sqrt{7}-\sqrt{2}\right).\left(\sqrt{7}+\sqrt{2}\right)\)
\(\left(\sqrt{3}+\sqrt{5}\right)^2\)
\(\left(\sqrt{8+3\sqrt{7}}\right)+\left(\sqrt{8-3\sqrt{7}}\right)\)
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 = \(\sqrt{11-4\sqrt{7}}-\sqrt{2}\times\sqrt{8+3\sqrt{7}}\)
B= \(\left(\sqrt{2}-\sqrt{3-\sqrt{5}}\right)\sqrt{2}\)
C= \(\sqrt{4-\sqrt{7}}-\sqrt{4}+\sqrt{7}\)
D= \(\sqrt{3}-\sqrt{2}-\sqrt{\sqrt{3}+\sqrt{2}}\)
E= \(\sqrt{4+2\sqrt{2}}.\sqrt{2+\sqrt{2+\sqrt{2}}}.\sqrt{2-\sqrt{2+\sqrt{2}}}\)
F= \(\left(\sqrt{2}-\sqrt{3+\sqrt{5}}\right)\sqrt{2}+2\sqrt{5}\)
G= \(\left(\sqrt{14}-\sqrt{10}\right).\left(\sqrt{6+\sqrt{35}}\right)\)
H= \(\sqrt{11-4\sqrt{7}}-\sqrt{2}.\sqrt{8+3\sqrt{7}}\)
\(\sqrt{4+2\sqrt[]{}3}\)
\(\left(\sqrt{ }7+\sqrt{ }3\right)^2\)
\(\left(\sqrt{ }5-\sqrt{ }3+1\right)\left(\sqrt{ }5-1\right)\)
\(\left(5\sqrt{ }3-2\sqrt{ }7\right)\left(5\sqrt{ }3+2\sqrt{ }7\right)\)
tính các biểu thức sau
1. Tính
a. \(\left(4+\sqrt{15}\right)\left(\sqrt{10}-\sqrt{6}\right)\sqrt{4-\sqrt{15}}\)
b.\(\sqrt{3-\sqrt{5}}\left(\sqrt{10}-\sqrt{2}\right)\left(3+\sqrt{5}\right)\)
c.\(\dfrac{\sqrt{\sqrt{5}+2}+\sqrt{\sqrt{5}-2}}{\sqrt{\sqrt{5}+1}}-\sqrt{3-2\sqrt{2}}\)
Rút gọn biểu thức
a. \(\left(2\sqrt{5}-\sqrt{7}\right)\left(2\sqrt{5}+\sqrt{7}\right)\)
b.\(\left(5\sqrt{2}+2\sqrt{3}\right)\left(2\sqrt{3}-5\sqrt{2}\right)\)
c. \(\sqrt{9+4\sqrt{5}}\)
d. \(\sqrt{14-6\sqrt{5}}+\sqrt{14+6\sqrt{5}}\)
e. \(\sqrt{55-6\sqrt{6}}\)
f. \(\sqrt{21-6\sqrt{6}}\)
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)\(\dfrac{1}{\sqrt{2}+\sqrt{2+\sqrt{3}}}+\dfrac{1}{\sqrt{2}-\sqrt{2-\sqrt{3}}}\)
(1+\(\sqrt{3}\) -\(\sqrt{2}\)).(1+\(\sqrt{3}+\sqrt{2}\) )
\(\left(\sqrt{3-\sqrt{5}}+\sqrt{3+\sqrt{5}}\right)^2\)
\(\left(\sqrt{\sqrt{11}+\sqrt{7}}-\sqrt{\sqrt{11}-\sqrt{7}}\right)^2\)
1) Tính
a) \(\sqrt{46-6\sqrt{5}}-\sqrt{29-12\sqrt{5}}\)
b) \(\sqrt{13-\sqrt{160}}-\sqrt{53+4\sqrt{90}}\)
c) \(\left(3-\sqrt{2}\right)\sqrt{7+4\sqrt{3}}\)
d) \(\left(\sqrt{7}-\sqrt{3}\right)\sqrt{10+2\sqrt{21}}\)
e) \(\left(3\sqrt{2}+10\right)\sqrt{38-12\sqrt{5}}\)
