Rút gọn :\(A=\frac{\sqrt{6+2.\left(\sqrt{6}+\sqrt{3}+\sqrt{2}\right)}-\sqrt{6-2.\left(\sqrt{6}-\sqrt{3}-\sqrt{2}\right)}}{\sqrt{2}}\)
.Làm ngắn các câu sau
a)\(\left(5+2\sqrt{6}\right)\left(49-20\sqrt{6}\right)\sqrt{5-2\sqrt{6}}\)
b) \(\frac{\sqrt{3-\sqrt{5}}.\left(3+\sqrt{5}\right)}{\sqrt{10}+\sqrt{2}}\)
Tính
\(\left(\sqrt{2}+1\right)\left(\sqrt{3}+1\right)\left(\sqrt{6}+1\right)\left(5-2\sqrt{2}-\sqrt{3}\right)\)
1.Rút gọn:
a) \(A=\sqrt{2+\sqrt{3}.}\sqrt{2+\sqrt{2+\sqrt{3}}}.\sqrt{2-\sqrt{2+\sqrt{3}}}\)
b) \(B=\left(\frac{\sqrt{x}}{\sqrt{xy}-y}-\frac{\sqrt{y}}{\sqrt{xy}-x}\right).\left(x\sqrt{y}-y\sqrt{x}\right)\)
c) \(C=\sqrt{\left(3-\sqrt{5}\right)^2+\sqrt{6}-2\sqrt{5}}\)
Rút gọn:
\(A=\left(\frac{4x\sqrt{x}+3x+9}{x+5\sqrt{x}+6}-\frac{3-\sqrt{x}}{2+\sqrt{x}}\right)\div\left(\frac{\sqrt{x}}{3+\sqrt{x}}-\frac{3+4\sqrt{x}}{x+5\sqrt{x}+6}\right)\)
\(B=\left(x-\sqrt{x}-2\right)\left(\dfrac{3}{\sqrt{x}-2}-\dfrac{4-\sqrt{x}}{x-2\sqrt{x}}\right)\)
Tìm ĐKXĐ:
a) \(\dfrac{3}{\sqrt{12x-1}}\)
b) \(\sqrt{\left(3x+2\right)\left(x-1\right)}\)
c) \(\sqrt{3x-2}\) .\(\sqrt{x-1}\)
d) \(\sqrt{\dfrac{-2\sqrt{6}+\sqrt{23}}{-x+5}}\)
Tính:
\(a,-0,8.\sqrt{\left(-0,125\right)^2}\)
\(b,\sqrt{\left(-2\right)^6}+\sqrt{\left(-3\right)^4}\)
\(c,\sqrt{3+2\sqrt{2}}-\sqrt{2}\)
\(d,\sqrt{9-4\sqrt{5}}-\sqrt{5}\)
\(e,\sqrt{16-6\sqrt{7}}-2\sqrt{7}\)
\(g,\sqrt{30+12\sqrt{6}}+\sqrt{30-12\sqrt{16}}\)
Tìm x để B=3A,biếtA=\(\left(\frac{5+2\sqrt{6}}{\sqrt{3}+\sqrt{2}}+\frac{5-2\sqrt{6}}{\sqrt{3}-\sqrt{2}}\right)\) /\(\left(\frac{1}{2\sqrt{5}+3\sqrt{2}}-\frac{1}{2\sqrt{5}-3\sqrt{2}}\right)\)
B=\(\frac{2x^4-x^3+2x^2+x-4}{2x^3-x^2-2x+1}\)
\(1.\left(\sqrt{5}-\sqrt{6}\right)^2\) \(6.\left(2\sqrt{5}-\sqrt{7}\right)\left(2\sqrt{5}+\sqrt{7}\right)\)
\(2.\left(\sqrt{3}-\sqrt{5}\right)^2\) \(7.\left(5\sqrt{2}+2\sqrt{3}\right)\left(2\sqrt{3}-5\sqrt{2}\right)\)
\(3.\left(2\sqrt{2}+\sqrt{3}\right)^2\) \(8.\sqrt{\left(5+2\sqrt{6}\right)^2}-\sqrt{\left(5-2\sqrt{6}\right)^2}\)
\(4.\left(\sqrt{4}-\sqrt{17}\right)^2\) \(9.\sqrt{\left(\sqrt{7}-2\right)^2}+\sqrt{\left(\sqrt{7}+2\right)^2}\)
\(5.\sqrt{\left(\sqrt{5}-3\right)^2}\) \(10.\sqrt{\left(\sqrt{3}+\sqrt{2}\right)^2}+\sqrt{\left(\sqrt{3}-\sqrt{2}\right)^2}\)