题目

先化简，再求值： ，其中a=2． 答案：a+1a2−2a+1÷(2+3−aa−1) =a+1(a−1)2÷2(a−1)+3−aa−1 =a+1(a−1)2÷a+1a−1 =a+1(a−1)2×a−1a+1 =1a−1 当a=2时，原式 =12−1=1 ．

查看本题答案和解析