2x(x-3)-(x-3)(x+6)=x²+12

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2x(x-3)-(x-3)(x+6)=x²带李+12
2x^2-6x-(x^2+3x-18)=x^2+12
-9x+6=0
x= 2/橘行帆圆雹3

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支持上面解法

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