Question

Giải pt:

\(x-3\sqrt{x-3}-3=0\)

Answer 1

ĐKXĐ: \(x\ge3\)

\(x-3\sqrt{x-3}-3=0\Rightarrow x-3-3\sqrt{x-3}=0\)

\(\Rightarrow\sqrt{x-3}\left(\sqrt{x-3}-3\right)=0\Rightarrow\left[{}\begin{matrix}\sqrt{x-3}=0\\\sqrt{x-3}=3\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=3\\x=12\end{matrix}\right.\)

Answer 2

ĐK: `x>=3`

`x-3\sqrt(x-3)-3=0`

`<=>(x-3)-3\sqrt(x-3)=0`

`<=>\sqrt(x-3) (\sqrt(x-3)-3)=0`

\(\Leftrightarrow\left[{}\begin{matrix}\sqrt{x-3}=0\\\sqrt{x-3}=3\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=3\\x=12\end{matrix}\right.\)

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Answer 3

ĐK: \(x\ge3\)

\(PT\Leftrightarrow\sqrt{x-3}\left(\sqrt{x-3}-3\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=3\left(tm\right)\\x-3=9=>x=12\left(tm\right)\end{matrix}\right.\)

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