化简：(1-a-1分之1)除以(a平方-2a+1)(a+2)分之a平方-4
问题描述：
化简：(1-a-1分之1)除以(a平方-2a+1)(a+2)分之a平方-4
答
[1-1/(a-1)]÷[(a^2-4)/(a^2-2a+1)(a+2)]
=[1-1/(a-1)]÷[(a-2)(a+2)/(a^2-2a+1)(a+2)]
=[1-1/(a-1)]÷[(a-2)/(a^2-2a+1)]
=[(a-1-1)/(a-1)]÷[(a-2)/(a-1)^2]
=[(a-2)/(a-1)]÷[(a-2)/(a-1)^2]
=(a-2)/(a-1)*(a-1)^2/(a-2)
=a-1