Rút gọn các biểu thức sau: A =\(\dfrac{\sqrt{5}+2}{\sqrt{5}-2}+\dfrac{\sqrt{5}-2}{\sqrt{5}+2}\)
B= \(\dfrac{1}{1-\sqrt{2}}-\sqrt{\left(\sqrt{2}-3\right)^2}\) C= \((\sqrt{\dfrac{6}{5}}-\sqrt{\dfrac{5}{6}}).\sqrt{30}\)
D= (\(2+\dfrac{3+\sqrt{3}}{\sqrt{3}+1})\left(2+\dfrac{3-\sqrt{3}}{1-\sqrt{3}}\right)\)
E= \(\dfrac{2}{x-1}.\sqrt{\dfrac{x^2-2x+1}{4x^2}}\)
F= \(\left(\dfrac{1}{\sqrt{x}+x}-\dfrac{2-\sqrt{x}}{\sqrt{x}+1}\right):\left(\dfrac{x+1}{\sqrt{x}}-2\right)\)
G= \(\left(\dfrac{2\sqrt{x}+4}{x-4}+\dfrac{2\sqrt{x}}{\sqrt{x}-2}\right).\dfrac{\sqrt{x}}{\sqrt{x}+x}\)
Giúp mình với.
