ĐKXĐ: \(x\ge3\)
\(pt\Leftrightarrow\sqrt{x-3}-3\sqrt{\left(x-3\right)\left(x+3\right)}=0\)
\(\Leftrightarrow\sqrt{x-3}\left(1-3\sqrt{x+3}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}\sqrt{x-3}=0\\3\sqrt{x+3}=1\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}x-3=0\\x+3=\dfrac{1}{9}\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=3\left(tm\right)\\x=-\dfrac{26}{9}\left(ktm\right)\end{matrix}\right.\)
\(ĐK:x\ge3\\ PT\Leftrightarrow\sqrt{x-3}\left(1-3\sqrt{x+3}\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x-3=0\\\sqrt{x+3}=\dfrac{1}{3}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x+3=\dfrac{1}{9}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\left(tm\right)\\x=-\dfrac{26}{9}\left(ktm\right)\end{matrix}\right.\Leftrightarrow x=3\)
