怎么都存在呢
幼苗
共回答了14个问题采纳率:92.9% 举报
1、原式=((a-1)(a-1))/(a-1)-a^2/(a-1)
=(a^2-2a+1-a^2)/(a-1)
=(1-2a)/(a-1)
2、原式=4/(a+2)+((a+2)(a-2))/(a+2)
=(4+(a+2)(a-2))/(a+2)
=(4+a^2-2^2)/(a+2)
=a^2/(a+2)
3、原式=(x+3)/((x-3)(x+3))-(x-3)/((x-3)(x+3))
=((x+3)-(x-3))/((x-3)(x+3))
=6/(x^2-9)
希望对你有所帮助!
1年前
10