a: \(=4\sqrt{5}-\left|2-\sqrt{5}\right|+\sqrt{\dfrac{16}{5}}\)
\(=4\sqrt{5}-\sqrt{5}+2+\dfrac{4}{5}\sqrt{5}\)
\(=\dfrac{19}{5}\sqrt{5}+2\)
b: \(=\dfrac{-\sqrt{3}\left(1-\sqrt{2}\right)}{1-\sqrt{2}}+\dfrac{\sqrt{3}\left(6+\sqrt{3}\right)}{\sqrt{3}}-\dfrac{13\left(4-\sqrt{3}\right)}{\left(4-\sqrt{3}\right)\left(4+\sqrt{3}\right)}\)
\(=-\sqrt{3}+6+\sqrt{3}-4+\sqrt{3}=2+\sqrt{3}\)
thực hiện phép tính
\(\left(\dfrac{15}{\sqrt{6}+1}+\dfrac{4}{\sqrt{16}-2}-\dfrac{12}{3-\sqrt{16}}\right).\left(\sqrt{6}+11\right)\)
thực hiện phép tính sau: \(\dfrac{\sqrt{3}+\sqrt{2}-1}{2+\sqrt{6}}+\dfrac{\sqrt{2}-\sqrt{3}}{\sqrt{2}+1}\left(\dfrac{\sqrt{3}}{2-\sqrt{6}}+\dfrac{\sqrt{3}}{2+\sqrt{6}}\right)-\dfrac{1}{\sqrt{2}}\)
CM: \(\left(\dfrac{2}{\sqrt{6}-1}+\dfrac{3}{\sqrt{6}-2}+\dfrac{3}{\sqrt{6}-3}\right).\dfrac{5}{9\sqrt{6}+4}=\dfrac{1}{2}\)
1.thực hiện phép tính: \(\left(3\sqrt{8}-\sqrt{18}+5\sqrt{\dfrac{1}{2}}+\sqrt{50}\right).3\sqrt{2}\)
2.giải pt:\(\sqrt{4x^2-4x+1}-5=2\)
Tính:
\(a.\) \(A=\sqrt{12}-2\sqrt{48}+\dfrac{7}{5}\sqrt{75}\)
\(b.\) \(B=\sqrt{14-6\sqrt{5}}+\sqrt{\left(2-\sqrt{5}\right)^2}\)
\(c.\) \(C=\left(\sqrt{6}-\sqrt{2}\right)\sqrt{2+\sqrt{3}}\)
\(d.\) \(D=\dfrac{5+\sqrt{5}}{\sqrt{5}+2}+\dfrac{\sqrt{5}-5}{\sqrt{5}}-\dfrac{11}{2\sqrt{5}+3}\)
I. Thực hiện phép tính
a. \(\left(\dfrac{2+\sqrt{5}}{2-\sqrt{5}}-\dfrac{2-\sqrt{5}}{2+\sqrt{5}}\right)\cdot\dfrac{\sqrt{2}}{23}\)
b. \(\sqrt{\left(5-2\sqrt{6}\right)\left(4-2\sqrt{3}\right)}\)
Rút gọn các biểu thức sau:
a) \(\dfrac{4}{\sqrt{11}-3}-\dfrac{5}{4+\sqrt{11}}\)
b) \(\left(\dfrac{3\sqrt{x}}{x-2\sqrt{x}}-\dfrac{2}{\sqrt{x}+3}\right):\dfrac{\sqrt{x}+13}{x+6\sqrt{x}+9}\) với x>0;x\(\ne\)4
1)tính
a)\(\left(\dfrac{1}{5}\sqrt{500}-3\sqrt{45}+5\sqrt{20}\right):\sqrt{5}\)
b)\(\left(\dfrac{\sqrt{3}+1}{\sqrt{3}-1}-\dfrac{\sqrt{3}-1}{\sqrt{3}+1}\right).\sqrt{\dfrac{1}{48}}\)
c)\(\left(\dfrac{2\sqrt{3}+3}{\sqrt{3}+2}+\dfrac{2\sqrt{2}}{\sqrt{2}+1}\right):\left(\sqrt{12}+\sqrt{18}\right)\)
Chứng minh các đẳng thức:
a) \(\sqrt{\sqrt{5}-\sqrt{3-\sqrt{29-12\sqrt{5}}}}\)=1
b)\(\dfrac{\left(5+2\sqrt{6}\right)\sqrt{5-2\sqrt{6}}}{\sqrt{2}+\sqrt{3}}\)-1 =0
c) \(\sqrt{26+15\sqrt{3}}+\sqrt{26-15\sqrt{3}}-5\sqrt{\dfrac{3}{2}}=\dfrac{\sqrt{6}}{2}\)
