\(P=\dfrac{x-3\sqrt{x}+3\sqrt{x}}{x-9}=\dfrac{x}{x-9}\)
Để P=2 thì x=2x-18
=>-x=-18
hay x=18
\(P=\dfrac{\sqrt{x}}{\sqrt{x}+3}+\dfrac{3\sqrt{x}}{x-9}\);\(ĐK:x\ge0;x\ne9\)
\(P=\dfrac{\sqrt{x}\left(\sqrt{x}-3\right)+3\sqrt{x}}{\left(\sqrt{x}-3\right)\left(\sqrt{x}+3\right)}\)
\(P=\dfrac{x-3\sqrt{x}+3\sqrt{x}}{\left(\sqrt{x}-3\right)\left(\sqrt{x}+3\right)}\)
\(P=\dfrac{x}{x-9}\)
\(P=2\)
\(\Leftrightarrow\dfrac{x}{x-9}=2\)
\(\Leftrightarrow\dfrac{x}{x-9}=\dfrac{2\left(x-9\right)}{x-9}\)
\(\Leftrightarrow x=2x-18\)
\(\Leftrightarrow x=18\left(tm\right)\)
Vậy \(x=18\) thì \(P=2\)
