a) ĐKXĐ: \(x\ge0\)
\(pt\Leftrightarrow\left(\sqrt{x}-3\right)^2=0\Leftrightarrow\sqrt{x}=3\Leftrightarrow x=9\left(tm\right)\)
2) ĐKXĐ: \(x\ge2\)
\(pt\Leftrightarrow\sqrt{\left(x-2\right)\left(x+2\right)}-3\sqrt{x-2}=0\)
\(\Leftrightarrow\sqrt{x-2}\left(\sqrt{x+2}-3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}\sqrt{x-2}=0\\\sqrt{x+2}=3\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}x-2=0\\x+2=9\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=2\left(tm\right)\\x=7\left(tm\right)\end{matrix}\right.\)
a: \(\Leftrightarrow\sqrt{x}-3=0\)
hay x=9
b: \(\Leftrightarrow\sqrt{x-2}\left(\sqrt{x+2}-3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-2=0\\x+2=9\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=2\\x=7\end{matrix}\right.\)
