∵x²+2ax+a+6=0两个相等的实根
∴Δ=4a²-4a-24=0
∴a=-2或3
[(a-2)/（a²-1）]÷[(a-2)-(a-2)/(a-1)]=1/[(a+1)(a-2)]=1/4“1/[(a+1)(a-2)]=1/4”？我化简出来是1/a(a-1)啊！[(a-2)/（a²-1）]÷[(a-2)-(a-2)/(a-1)]=[1/(a-1)(a+1)]÷[1-1/(a-1)]=[1/(a-1)(a+1)]÷[(a-2)/(a-1)]=[1/(a-1)(a+1)][(a-1)/(a-2)]=1/[(a+1)(a-2)]你可能是算错了，你再算算看