题目

1/(a-1)-(1-3a)/(2-2a)

提问时间：2021-01-20

答案

原式=1/(a-1)+(1-3a)/[2(a-1)] 通分,最简公分母是2(a-1)
=2/[2(a-1)]+(1-3a)/[2(a-1)]
=(2+1-3a)/[2(a-1)]
=(3-3a)/[2(a-1)]
=-3(a-1)/[2(a-1)],约去(a-1)
=-3/2