E = ( \(\dfrac{\sqrt{x}}{\sqrt{x-1}}\)- \(\dfrac{1}{x-\sqrt{x}}\)) : ( \(\dfrac{1}{\sqrt{x+1}}\)+\(\dfrac{2}{\sqrt{x-1}}\))
a) ta có ĐKXĐ của E là x \(\ne\) 1
x \(\ne\) 0
x \(\ne\) -1
b) ( \(\dfrac{\sqrt{x}}{\sqrt{x}-1}\)- \(\dfrac{\sqrt{1}}{x-\sqrt{x}}\)) : ( \(\dfrac{1}{\sqrt{x}+1}\)+\(\dfrac{2}{\sqrt{x}-1}\))
= (\(\dfrac{\sqrt{x}}{\sqrt{x}-1}\)- \(\dfrac{1}{\sqrt{x}\left(\sqrt{x}-1\right)}\)) :(\(\dfrac{1}{\sqrt{x}+1}\)+ \(\dfrac{2}{x+1}\))
= ( \(\dfrac{\sqrt{x}.\sqrt{x}-1}{\sqrt{x}\left(\sqrt{x}-1\right)}\)) : (\(\dfrac{1\left(x-1\right)+2\sqrt{x+1}}{\left(\sqrt{x}+1\right)\left(x-1\right)}\))
= ( \(\dfrac{x-1}{\sqrt{x}\left(\sqrt{x}-1\right)}\)) : \(\dfrac{x-1+2\sqrt{x}+2}{\left(\sqrt{x}+1\right)\left(x-1\right)}\)
= \(\dfrac{1}{\sqrt{x}}\): \(\dfrac{\left(x-1\right)+2\left(\sqrt{x}+1\right)}{\left(\sqrt{x}+1\right)\left(x-1\right)}\)
= \(\dfrac{1}{\sqrt{x}}\). \(\dfrac{1}{2}\)
= \(\dfrac{1}{2\sqrt{x}}\)