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检查谢谢已知x-4/x=6，求代数式2x²-20x/x²-14x+4除（1-x-12/2-x）的值x-4/x=6x²-4=6xx²-6x=4所以原式=(2x²-12x-8x)/(x²-6x-8x+4)÷[(x²-3x+2-12)/(2-x)]=(8-8x)/(4-8x+4)×[(2-x)/(x²-6x+3x-10)]=1×(2-x)/(4+3x-10)=-(x-2)/[3(x-2)]=-1/3