题目

    (1) 解不等式组: (2) 计算: 答案: 解: {2x−4>3(x−2)①x−72<4x②,解不等式①得:x<2,解不等式②得:x>−1,所以原不等式组的解集为−1<x<2 解:x+2x2−1÷(1x+1−1−x)=x+2(x+1)(x−1)÷(1x+1−x+1x+1−x2+xx+1)=x+2(x+1)(x−1)÷1−x−1−x2−xx+1=x+2(x+1)(x−1)·x+1−x(x+2)=1x−x2.
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