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计算:-4/(x^2-4)-1/(2-x) x-7/(x-3)+1/3-x

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计算:-4/(x^2-4)-1/(2-x) x-7/(x-3)+1/3-x
-4/(x^2-4)-1/(2-x)
=-4/(x+2)(x-2) + 1/(x-2)
=(-4+x+2)/(x+2)(x-2)
=(x-2)/(x+2)(x-2)
=1/(x+2)
x-7/(x-3)+1/(3-x)
=x - 7/(x-3) - 1/(x-3)
=(x^2-3x-7-1)/(x-3)
=(x^2-3x-8)/(x-3)
再问: 第二题貌似错了
再答: (x-7)/(x-3)+1/(3-x) x-7 是分子吗? =(x -7)/(x-3) - 1/(x-3) =(x-7-1)/(x-3) =(x-8)/(x-3)