`1) C1:x²-3x+2=0`
`<=>(x^2-x)+(-2x+2)=0`
`<=>x(x-1)-2(x-1)=0`
`<=>(x-1)(x-2)=0`
`<=>`\(\left[ \begin{array}{l}x=1\\x=2\end{array} \right.\)
`C2:x²-3x+2=0`
`<=>(x^2-2x)+(-x+2)=0`
`<=>x(x-2)-(x-2)=0`
`<=>(x-2)(x-1)=0`
`<=>`\(\left[ \begin{array}{l}x=2\\x=1\end{array} \right.\)
`C3:x²-3x+2=0`
`<=>(x^2-1)+(-3x+3)=0`
`<=>(x-1)(x+1)-3(x-1)=0`
`<=>(x-1)(x-2)=0`
`<=>`\(\left[ \begin{array}{l}x=1\\x=2\end{array} \right.\)
`2)C1: 4x²-12x+5=0`
`<=>(4x²-2x)+(-10x+5)=0`
`<=>2x(2x-1)-5(2x-1)=0`
`<=>(2x-1)(2x-5)=0`
`<=>`\(\left[ \begin{array}{l}x=\cfrac12\\x=\cfrac52\end{array} \right.\)
`C2: 4x²-12x+5=0`
`<=>(4x²-10x)+(-2x+5)=0`
`<=>2x(2x-5)-(2x-5)=0`
`<=>(2x-5)(2x-1)=0`
`<=>`\(\left[ \begin{array}{l}x=\cfrac52\\x=\cfrac12\end{array} \right.\)
`C3: 4x²-12x+5=0`
`<=>(4x²-1)+(-12x+6)=0`
`<=>(2x-1)(2x+1)-6(2x-1)=0`
`<=>(2x-1)(2x-5)=0`
`<=>`\(\left[ \begin{array}{l}x=\cfrac12\\x=\cfrac52\end{array} \right.\)
