Question

giải phương trình \(\sqrt{x^2-6x+9}=x-3\)

Answer 1

\(\sqrt{x^2-6x+9}=x-3\left(x\ge3\right)\)

\(\Leftrightarrow\sqrt{\left(x-3\right)^2}=x-3\)

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

\(\Leftrightarrow\left[{}\begin{matrix}x\in R\left(x\ge3\right)\\x=3\end{matrix}\right.\)

\(\Leftrightarrow x\in R\left(x\ge3\right)\)

Answer 2

\(\sqrt{\left(x-3\right)^2}\) \(=x-3\)

⇔ \(\left|x-3\right|=x-3\)

\(\Leftrightarrow x-3=x-3 \\ \)

⇔

Answer 3

sorry mình ấn nhầm