$\\$
`(3x-1)^2 - 4 (x-2)^2=0`
`⇔ (9x^2 - 6x + 1) - 4 (x^2 - 4x + 4)=0`
`⇔ 9x^2- 6x + 1 - 4x^2 + 16x - 16=0`
`⇔ 5x^2 + 10x - 15=0`
`⇔ 5 (x^2 +2x - 3)=0`
`⇔ x^2 +2x-3=0`
`⇔ x^2 - x + 3x - 3=0`
`⇔ (x^2 - x)+(3x-3)=0`
`⇔ x (x-1)+3(x-1)=0`
`⇔ (x-1)(x+3)=0`
`⇔` \(\left[ \begin{array}{l}x-1=0\\x+3=0\end{array} \right.\) $\\$ `<=>` \(\left[ \begin{array}{l}x=1\\x=-3\end{array} \right.\)
Vậy pt có tập nghiệm : `S={1;-3}`
