(a-1)/(a^2-4a+ 4)/(a^2-1)/(a^2-4)
问题描述:
(a-1)/(a^2-4a+ 4)/(a^2-1)/(a^2-4)
答
=(a-1)/(a-2)²×(a+2)(a-2)/(a+1)(a-1)
=(a+2)/(a-2)(a+1)
=(a+2)/(a²-a-2)