(a-1-1)/(a-1)÷(a-2)²/(a+1)(a-1)∵a≠1,a≠2分子分母同乘以(a-1)/(a-2)1÷(a-2)/(a+1)=(a+1)/(a-2)=1+3/(a-2)将a=-2代入得原式=1-3/4=1/4如果满意请采纳,如有疑问请继续追问,谢谢!