` \sqrt{x^2 - 4x + 4} = \sqrt{4x^2 - 12x + 9} `
` <=> \sqrt{(x - 2)^2} = \sqrt{(2x - 3)^2} `
` <=> |x - 2| = |2x - 3| `
` <=> ` \(\left[ \begin{array}{l}x-2=2x-3\\2-x=2x-3\\x-2=3-2x\\2-x=3-2x\end{array} \right.\)
` <=> ` \(\left[ \begin{array}{l}x-2x=-3+2\\x+2x=2+3\\x+2x=3+2\\-x+2x=3-2\end{array} \right.\)
` <=> ` \(\left[ \begin{array}{l}-x=-1\\3x=5\\3x=5\\x=1\end{array} \right.\)
` <=> ` \(\left[ \begin{array}{l}x=1\\x=\frac{5}{3}\end{array} \right.\)
Vậy phương trình có tập nghiệm là: ` S = {1 ; 5/3} `
