第1个回答 推荐于2021-01-17
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第2个回答 2014-01-29
先化简后面那括号里的(a^2-1-3)/(a+1)=(a^2-4)/(a+1)
然后除就是倒过来乘,把(a+1)约去
就是(a^2+2a)/(a^2-4)=(a+2)/(a-2)是最终结果
不清楚的话可以追问
第3个回答 2014-01-29
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追问你第二步算错了,
追答哪错了
追问好像是第三步,我有点不清楚了。反正不是你最后写的那个
第4个回答 2014-01-29
原式=a(a+2)/(a+1)÷﹙a²-1-3)/(a+1)
=a(a+2)/(a+1)×(a+1)/[(a+2)(a-2)]
=a/(a-2)
第5个回答 2014-01-29
(4)
原式
= (a²+2a) / (a+1) ÷ (a-1-3/(a+1))
= (a²+2a) / (a+1) ÷ ((a²-1-3)/(a+1)
= (a²+2a) / (a+1) × (a+1) / (a²-4)
= a(a+2) / (a²-4)
= a /(a-2)