\(\sqrt{x^2-6x+9}=4-x\)
\(\Leftrightarrow\sqrt{\left(x-3\right)^2}=4-x\)
\(\Leftrightarrow\left|x-3\right|=4-x\)
\(\Leftrightarrow\left[{}\begin{matrix}x-3=4-x\\x-3=x-4\left(vn\right)\end{matrix}\right.\)
\(\Leftrightarrow x=\dfrac{7}{2}\)
\(\sqrt{x^2-6x+9}=4-x\)
\(\Leftrightarrow\left(x-3\right)^2=\left(4-x\right)^2\)
\(\Leftrightarrow\left(x-3\right)^2-\left(x-4\right)^2=0\)
\(\Leftrightarrow\left(x-3-x+4\right)\left(x-3+x-4\right)=0\)
\(\Leftrightarrow2x-7=0\)
hay \(x=\dfrac{7}{2}\left(nhận\right)\)
\(\sqrt{x^2-6x+9}=4-x\left(đk:x\le4\right)\Leftrightarrow\sqrt{\left(x-3\right)^2}=4-x\Leftrightarrow\left|x-3\right|=4-x\Leftrightarrow\left[{}\begin{matrix}x-3=4-x\\3-x=4-x\left(loai\right)\end{matrix}\right.\Leftrightarrow x=\dfrac{7}{2}}\)
