\(\left(\dfrac{1}{\sqrt{a}-1}-\dfrac{1}{\sqrt{a}}\right):\left(\dfrac{\sqrt{a}+1}{\sqrt{a}-2}-\dfrac{\sqrt{a}+1}{\sqrt{a}-1}\right)\)
\(\left(\dfrac{1}{1-\sqrt{x}}-\dfrac{1}{1+\sqrt{x}}\right)\left(\dfrac{1}{\sqrt{x}}+1\right)\)
giúp với ạ. Mai thi r