đk x >= 0 ; x khác 1
\(P=\left(\dfrac{x+\sqrt{x}+1+\sqrt{x}}{x+\sqrt{x}+1}\right):\dfrac{\sqrt{x}+1}{\left(\sqrt{x}-1\right)\left(x+\sqrt{x}+1\right)}\)
\(=\left(\dfrac{\left(\sqrt{x}+1\right)^2}{x+\sqrt{x}+1}\right):\dfrac{\sqrt{x}+1}{\left(\sqrt{x}-1\right)\left(x+\sqrt{x}+1\right)}=x-1\)