a/ \(A=\sqrt{6-2\sqrt{5}}-\sqrt{5}\)\(=\sqrt{\left(\sqrt{5}\right)^2-2\sqrt{5}+1^2}-\sqrt{5}\)\(=\sqrt{\left(\sqrt{5}-1\right)^2}-\sqrt{5}\)\(=\sqrt{5}-1-\sqrt{5}\)\(=-1.\)
Bạn kiểm tra lại câu b với c đi, hình như sai đề rồi.
tính P= a3 +b3- 3(a+b)+2018. Biết
a=\(\sqrt[3]{5+2\sqrt{6}}+\sqrt[3]{5-2\sqrt{6}}\)
\(b=\sqrt[3]{17+12\sqrt{2}}+\sqrt[3]{17-12\sqrt{2}}\)
Chứng minh A,B là số nguyên với:
A = \(\sqrt{6-2\sqrt{5}}\)- \(\sqrt{6+2\sqrt{5}}\)
B= \(\frac{\sqrt{3-2\sqrt{2}}}{\sqrt{17}-12\sqrt{2}}-\frac{\sqrt{3+2\sqrt{2}}}{\sqrt{17+12\sqrt{2}}}\)
A= \(\sqrt{6+\sqrt{24}+\sqrt{8}+\sqrt{12}}-\sqrt{5+2\sqrt{6}}\)
B= \(\sqrt{12+\sqrt{60}+\sqrt{48}+\sqrt{80}}-\sqrt{8+2\sqrt{15}}\)
C= \(\sqrt{39+12\sqrt{10}+6\sqrt{2}+4\sqrt{5}}-\sqrt{38+12\sqrt{10}}\)
Tính:
\(a,-0,8.\sqrt{\left(-0,125\right)^2}\)
\(b,\sqrt{\left(-2\right)^6}+\sqrt{\left(-3\right)^4}\)
\(c,\sqrt{3+2\sqrt{2}}-\sqrt{2}\)
\(d,\sqrt{9-4\sqrt{5}}-\sqrt{5}\)
\(e,\sqrt{16-6\sqrt{7}}-2\sqrt{7}\)
\(g,\sqrt{30+12\sqrt{6}}+\sqrt{30-12\sqrt{16}}\)
Tính GTBT chứa căn:
a,\(\left(\sqrt{14}-3\sqrt{2}\right)^2\)+\(6\sqrt{28}\)
b,\(\left(\sqrt{6}-\sqrt{5}\right)^2\)-\(2\sqrt{120}\)
c,\(\left(2\sqrt{3}-3\sqrt{2}\right)^2+2\sqrt{6}+3\sqrt{24}\)
Tính :
a ) \(S=\frac{1}{\sqrt{1}\sqrt{3}}+\frac{1}{\sqrt{3}+\sqrt{5}}+\frac{1}{\sqrt{5}+\sqrt{7}}+.....+\)\(\frac{1}{\sqrt{2017}+\sqrt{2019}}\)
b ) \(S=\frac{1}{\sqrt{2}+\sqrt{4}}+\frac{1}{\sqrt{4}+\sqrt{6}}+....+\frac{1}{\sqrt{100}+\sqrt{102}}\)
c ) \(S=\frac{1}{\sqrt{1}+\sqrt{2}}+\frac{1}{\sqrt{2}+\sqrt{3}}+.....+\frac{1}{\sqrt{100}+\sqrt{101}}\)
d ) \(S=\frac{1}{\sqrt{3}+\sqrt{6}}+\frac{1}{\sqrt{6}+\sqrt{9}}+\frac{1}{\sqrt{9}+\sqrt{12}}+....+\frac{1}{\sqrt{2016}+\sqrt{2019}}\)
Rút gọn biểu thức
A = \(\frac{\sqrt{3}+\sqrt{11+6\sqrt{2}}-\sqrt{5+2\sqrt{6}}}{\sqrt{2}+\sqrt{6+2\sqrt{5}}-\sqrt{7+2\sqrt{10}}}\)
B = \(\sqrt{5\sqrt{3}+5\sqrt{48-10\sqrt{7+4\sqrt{3}}}}\)
C = \(\sqrt{2-\sqrt{3}}-\sqrt{2+\sqrt{3}}\)
D = \(\sqrt{28+6\sqrt{3}}-\sqrt{28-6\sqrt{3}}\)
E = \(6x+\sqrt{9x^2-12x+4}\)
F = \(5x-\sqrt{x^2+4x+4}\)
Rút gọn:
a) \(\sqrt{5\sqrt{3}+5\sqrt{48-10\sqrt{7+\sqrt{48}}}}\)
b) \(\dfrac{\sqrt{3}-\sqrt{5+\sqrt{24}}+\sqrt{\sqrt{72}+11}}{\sqrt{6+\sqrt{20}}+\sqrt{2}-\sqrt{7+\sqrt{40}}}\)
1. Rút gọn. a, B=\(\sqrt{2-\sqrt{2\sqrt{5}-2}}-\sqrt{2+\sqrt{2\sqrt{5}-2}}\) b,C=\(\frac{3\sqrt{10}+\sqrt{20}-3\sqrt{6}-\sqrt{12}}{\sqrt{5}-\sqrt{3}}\) c, C=\(\frac{\sqrt{2}+\sqrt{3}+\sqrt{6}+\sqrt{8}+\sqrt{16}}{\sqrt{2}+\sqrt{3}+\sqrt{4}}\)
