计算 x^2-4x+4分之x-2 - 2x+4 分之1 - 2x^2-8分之x-1

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计算 x^2-4x+4分之x-2 - 2x+4 分之1 - 2x^2-8分之x-1

计算 x^2-4x+4分之x-2 - 2x+4 分之1 - 2x^2-8分之x-1
计算 x^2-4x+4分之x-2 - 2x+4 分之1 - 2x^2-8分之x-1

计算 x^2-4x+4分之x-2 - 2x+4 分之1 - 2x^2-8分之x-1
x^2-4x+4分之x-2 - 2x+4 分之1 - 2x^2-8分之x-1
=(x-2)/(x-2)²-1/2(x+2)-(x-1)/2(x²-4)
=1/(x-2)-1/2(x+2)-(x-1)/2(x+2)(x-2)
=[2(x+2)-(x-2)-(x-1)]/2(x-2)(x+2)
=(2x+4-x+2-x+1)/2(x-2)(x+2)
=7/[2(x-2)(x+2)]

(x-2)/(x^2-4x+4)-1/(2x+4)-(x-1)/(2x^2-8)=(x-2)/(x-2)²-1/[2(x+2)]-(x-1)/[2(x+2)(x-2)]
=[2(x+2)-(x-2)-(x-1)]/[2(x-2)(x+2)]
...

全部展开

(x-2)/(x^2-4x+4)-1/(2x+4)-(x-1)/(2x^2-8)=(x-2)/(x-2)²-1/[2(x+2)]-(x-1)/[2(x+2)(x-2)]
=[2(x+2)-(x-2)-(x-1)]/[2(x-2)(x+2)]
=7/[2(x-2)(x+2)]
=7/(2x^2-8)

收起

原式=(x-2)/(x-2)²-1/2(x+2)-(x-1)/2(x²-4)
=1/(x-2)-1/2(x+2)-(x-1)/2(x+2)(x-2)
=[2(x+2)-(x-2)-(x-1)]/2(x-2)(x+2)
=(2x+4-x+2-x+1)/2(x-2)(x+2)
=7/[2(x-2)(x+2)]