先化简再求值:2a+2/a-1÷(a+1)+a²-1/a²-2a+1,其中a=1

问题描述:

先化简再求值:2a+2/a-1÷(a+1)+a²-1/a²-2a+1,其中a=1

原式=2(a+1)/(a-1)×1/(a+1)+(a+1)(a-1)/(a-1)²
=2/(a-1)+(a+1)/(a-1)
=(2+a+1)/(a-1)
=(a+3)/(a-1)
a=1则分母a-1=0
无意义
所以题目无解


(2a+2)/(a-1)÷(a+1)+(a²-1)/(a²-2a+1)
=2(a+1)/(a-1)÷(a+1)+(a+1)(a-1)/(a-1)²
=2/(a-1)+(a+1)/(a-1)
=(a+3)/(a-1)
化简的结果就是上面的
a=1不可以哦,因为此时分母为0是无意义的