x的3次方―4x+3x的2次方―12分解因式

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原式=x³乱慧+3x²清陪绝-4x-12
=x²答姿(x+3)-4(x+3)
=(x+3)(x²-4)
=(x+3)(x+2)(x-2)

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x的3次方―4x+3x的2次方―12
=?X+3??X+2??X-2?

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X^3-4X+3X^2-12=X^2(X-3)-4(X-3)=(X-3)(X^2-4)=(X-3)(X-2)(X+2)

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(x-2)(x+2)(x+3)

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