a) \(\dfrac{5-2\sqrt{ }5}{\sqrt{ }5-2}-\dfrac{11}{4+\sqrt{ }5} \)
b)\(\sqrt{9+4\sqrt{ }5-\sqrt{ }6-2\sqrt{ }5}\)
c)\(\sqrt{17-3\sqrt{ }32+\sqrt{ }17+\sqrt{ }32}\)
Giair phương trình:
1) \(\sqrt[5]{32-x^2}-\sqrt[5]{1-x^2}=4\)
2) \(\sqrt{x}+\sqrt[4]{20-x}=4\)
3) \(x^3+1=2\sqrt{3x-1}\)
4) \(\sqrt[3]{x-1}+3=\sqrt[4]{82-x}\)
5)
\(a.\left(x+3\sqrt{x}+2\right)\left(x+9\sqrt{x}+18\right)=168x\)
\(b.\sqrt{5x^2+14x+9}-\sqrt{x^2-x-20}=5\sqrt{x+1}\)
\(\sqrt[3]{9+4\sqrt{5}}\) - \(\sqrt[3]{9-4\sqrt{5}}\)
\(\sqrt{8x-4}-12\sqrt{\dfrac{2x-1}{9}}+\sqrt{18x-9}=5\)
Rút gọn căn thức bậc hai
b, \(\sqrt{8-2\sqrt{7}}\)
c, \(\sqrt{29-12\sqrt{5}}-\sqrt{9-4\sqrt{5}}\)
a)\(\sqrt{9+x}=5-\sqrt{4+2x}\)
b)\(\sqrt{8+3x}-\sqrt{5+3x}=\sqrt{5x-4}-\sqrt{5x-7}\)
CMR:\(\dfrac{1}{1+\sqrt{3}}+\dfrac{1}{\sqrt{5}+\sqrt{7}}+\dfrac{1}{\sqrt{9}+\sqrt{11}}+...+\dfrac{1}{\sqrt{97}+\sqrt{99}}>\dfrac{9}{4}\)
Giải phương trình:
a) \(x + \sqrt{9 -x^2} = 3 + 5x\sqrt{9 - x^2}\)
b) \(3\sqrt{1 - x^2} = 5\sqrt{1 + x} - 4\sqrt{1 - x} + x + 6\)
c) \(x + 2 + 4\sqrt{x^2 - x + 2} = 2\sqrt{6x^2 - x + 14}\)
Thực hiện phép tính:
1)A=\(\left(\dfrac{1}{3-\sqrt{5}}-\dfrac{1}{3+\sqrt{5}}\right)\) . \(\dfrac{5-\sqrt{5}}{\sqrt{5}-1}\)
2)B = \(\dfrac{1}{1 +\sqrt{2}}\) +\(\dfrac{1}{\sqrt{2}+\sqrt{3}}\)+.....+\(\dfrac{1}{\sqrt{99}+\sqrt{100}}\)
3)C = \(\sqrt[3]{7+5\sqrt{2}}\) - \(\sqrt[3]{7-5\sqrt{2}}\)
4) D = \(\sqrt[3]{9+4\sqrt{5}}\)+\(\sqrt[3]{9-4\sqrt{3}}\)