\(\sqrt{\dfrac{3}{7}}=\dfrac{\sqrt{3}.\sqrt{7}}{\left(\sqrt{7}\right)^2}=\dfrac{\sqrt{21}}{7}\)
\(\sqrt{\dfrac{3}{7}}=\sqrt{\dfrac{3.7}{7^2}}=\dfrac{\sqrt{21}}{7}\)
Rút gọn các biểu thức sau:
9, A = \(\sqrt{4+\sqrt{15}}-\sqrt{7-3\sqrt{5}}\)
10, A = \(\sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}}\)
11, A = \(\text{}\text{}\text{}\sqrt{12-3\sqrt{7}}-\sqrt{12+3\sqrt{7}}\)
12, A = \(\left(3\sqrt{2}+\sqrt{6}\right)\sqrt{6-3\sqrt{3}}\)
13, A = \(\sqrt{9-4\sqrt{5}}-\sqrt{14-6\sqrt{5}}\)
1.1/3-2√2 + 1/2+√5 2.1/√3+√7 + 2/1-√7 3.a-2√a/2-√a 4.x√y+y√x/√x+√y
1. A=\(\sqrt{4+\sqrt{ }7}\)+ \(\sqrt{4-\sqrt{ }7}\) 2. B=\(\dfrac{\sqrt{\sqrt{7-\sqrt{3}}}-\sqrt{\sqrt{7+\sqrt{3}}}}{\sqrt{\sqrt{7}-\sqrt{2}}}\) 3. C=\(\sqrt{6+2\sqrt{2\cdot\sqrt{3-\sqrt{4+2\sqrt{3}}}}}\) 4. D=\(\sqrt{5}-\sqrt{3-\sqrt{29-12\sqrt{5}}}\) 5. so sánh Cho A=\(\sqrt{11+\sqrt{96}}\) B=\(\dfrac{2\sqrt{2}}{\sqrt{1+\sqrt{2-\sqrt{3}}}}\) so sánh A và B
Tính (2/a3)×√8,1a3/1,6aa
So sánh A= 2√7 và B=2+√7
Tính :
a) \(\dfrac{7\sqrt{3}-\:3\sqrt{7}}{\sqrt{7}-\sqrt{3}}+\dfrac{4}{5-\sqrt{21}}-\:\dfrac{6\sqrt{7}}{\sqrt{3}}\)
b) \(\sqrt{\dfrac{2+2\sqrt{3}}{\sqrt{3}-\:1}}+\dfrac{\sqrt{2}}{1+\sqrt{3}}\sqrt{2\:-\sqrt{3}}\)
c) \(\sqrt{2\:-\sqrt{3}}.\:\left(\sqrt{2+\sqrt{3}}+\sqrt{2}\right)\)
1. A=\(\sqrt{4+\sqrt{7}}\) +\(\sqrt{4-\sqrt{7}}\)
2. B= \(\dfrac{\sqrt{\sqrt{7-\sqrt{3}}-\sqrt{7+\sqrt{3}}}}{\sqrt{7-\sqrt{2}}}\)
3. C=\(\sqrt{6+2\sqrt{2\cdot\sqrt{3-\sqrt{4+2\sqrt{3}}}}}\)
4. D=\(\sqrt{5}-\sqrt{3-\sqrt{29-12\sqrt{5}}}\)
5 E=\(\dfrac{1+\sqrt{5}}{\sqrt{2}+\sqrt{3}+\sqrt{5}}\) +\(\dfrac{1-\sqrt{5}}{\sqrt{2}-\sqrt{3-\sqrt{5}}}\)
6. so sánh Cho A=\(\sqrt{11+\sqrt{96}}\)
B= \(\dfrac{2\sqrt{2}}{1+\sqrt{2-\sqrt{3}}}\) so sánh A và b
Rút gọn biểu thức:
\(\dfrac{\sqrt{a-2}+2}{3}\left(\dfrac{\sqrt{a-2}}{3+\sqrt{a-2}}+\dfrac{a+7}{11-a}\right):\left(\dfrac{3\sqrt{a-2}+1}{a-3\sqrt{a-2}-2}-\dfrac{1}{\sqrt{a-2}}\right)\)
1, Rút gọn biểu thức số:
a, (4+\(\sqrt{7}\)) (\(\sqrt{14}-\sqrt{2}\)) \(\sqrt{4-\sqrt{7}}\)
b, \(\dfrac{4+\sqrt{7}}{3\sqrt{2}+\sqrt{4+\sqrt{7}}}\) + \(\dfrac{4-\sqrt{7}}{3\sqrt{2}-\sqrt{4-\sqrt{7}}}\)
\(A=\left(5+\frac{7-\sqrt{21}}{\sqrt{7}-\sqrt{3}}\right)\left(\sqrt{16-5\sqrt{7}}\right)\)
rút gọn biểu thức
