1: \(P=\left(\dfrac{-1}{\sqrt{x}-1}-\dfrac{1}{\sqrt{x}}\right):\left(\dfrac{2x+\sqrt{x}-1}{1-x}+\dfrac{2x\sqrt{x}+x-\sqrt{x}}{1+x\sqrt{x}}\right)\)
\(=\dfrac{-\sqrt{x}-\sqrt{x}+1}{\sqrt{x}\left(\sqrt{x}-1\right)}:\left(\dfrac{-\left(\sqrt{x}+1\right)\left(2\sqrt{x}-1\right)}{x-1}+\dfrac{\sqrt{x}\left(2\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}\right)\)
\(=\dfrac{-2\sqrt{x}+1}{\sqrt{x}\left(\sqrt{x}-1\right)}:\left[\left(2\sqrt{x}-1\right)\left(\sqrt{x}+1\right)\left(\dfrac{-1}{x-1}+\dfrac{\sqrt{x}}{\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}\right)\right]\)
\(=\dfrac{-2\sqrt{x}+1}{\sqrt{x}\left(\sqrt{x}-1\right)}:\left[\left(2\sqrt{x}-1\right)\left(\sqrt{x}+1\right)\left(\dfrac{-x+\sqrt{x}-1+x-\sqrt{x}}{\left(\sqrt{x}+1\right)\left(\sqrt{x}-1\right)\left(x-\sqrt{x}+1\right)}\right)\right]\)
\(=\dfrac{-2\sqrt{x}+1}{\sqrt{x}\left(\sqrt{x}-1\right)}:\left(\dfrac{-\left(2\sqrt{x}-1\right)}{\left(\sqrt{x}-1\right)\left(x-\sqrt{x}+1\right)}\right)\)
\(=\dfrac{-2\sqrt{x}+1}{\sqrt{x}\left(\sqrt{x}-1\right)}\cdot\dfrac{\left(\sqrt{x}-1\right)\left(x-\sqrt{x}+1\right)}{-2\sqrt{x}+1}=\dfrac{x-\sqrt{x}+1}{\sqrt{x}}\)
P=7/3
=>\(\dfrac{x-\sqrt{x}+1}{\sqrt{x}}=\dfrac{7}{3}\)
=>\(3x-3\sqrt{x}+3-7\sqrt{x}=0\)
=>\(3x-10\sqrt{x}+3=0\)
=>\(\left(\sqrt{x}-3\right)\left(3\sqrt{x}-1\right)=0\)
=>x=9 hoặc x=1/9
