解下列一元二次方程:(配方法)x方-3x+1=0和2x方+6=7x和3x方-9x+2=0

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x^2-3x+1=0
x^2-3x+2-1=0
(x-2)(x-1)=1

2x^2+6=7x
2x^2-7x+6=0
(x-2)(2x-3)=0

3x^2-9x+2=0
3x^2-9x+6-4=0
(x-1)(3x-6)=4

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