a: \(P=\dfrac{x-1}{\sqrt{x}}:\dfrac{x-1-\sqrt{x}+1}{\sqrt{x}\left(\sqrt{x}+1\right)}\)
\(=\dfrac{x-1}{x-\sqrt{x}}=\dfrac{\sqrt{x}+1}{\sqrt{x}}\)
b: Khi \(x=\dfrac{2}{2+\sqrt{3}}=4-2\sqrt{3}\) thì
\(P=\dfrac{\sqrt{3}-1+1}{\sqrt{3}-1}=\dfrac{\sqrt{3}}{\sqrt{3}-1}\)