`3-sqrt{49-14x+x^2}=1`
`⇔sqrt{(7-x)^2}=2`
`⇔|7-x|=2`
`⇔`\(\left[ \begin{array}{l}7-x=2\\7-x=-2\end{array} \right.\)
`⇔`\(\left[ \begin{array}{l}x=5\\x=9\end{array} \right.\)
`sqrt{(2x-1)^2}-1=0`
`⇔|2x-1|=1`
`⇔`\(\left[ \begin{array}{l}2x-1=1\\2x-1=-1\end{array} \right.\)
`⇔`\(\left[ \begin{array}{l}2x=2\\2x=0\end{array} \right.\)
`⇔`\(\left[ \begin{array}{l}x=1\\x=0\end{array} \right.\)
`sqrt{4x^2-4x+1}+x-3=0`
`⇔sqrt{(2x-1)^2}=3-x`
`⇔|2x-1|=3-x`
`⇔`\(\left[ \begin{array}{l}2x-1=3-x\\2x-1=x-3\end{array} \right.\)
`⇔`\(\left[ \begin{array}{l}3x=4\\x=-2\end{array} \right.\)
`⇔`\(\left[ \begin{array}{l}x=\dfrac{4}{3}\\x=-2\end{array} \right.\)
