Sửa đề: \(P=\left(\frac{\sqrt{x^3}+1}{\sqrt{x}+1}+\sqrt{x}\right):\left(x+1\right)\)
\(=\left(\frac{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}{\sqrt{x}+1}+\sqrt{x}\right):\left(x+1\right)\)
\(=\left(x-\sqrt{x}+1+\sqrt{x}\right):\left(x+1\right)\)
=(x+1):(x+1)
=1