问题 选择题 当x≠-1时,对于分式1x-1总有( )A.1x-1=2x+1B.1x-1=x+1x2-1C.1x-1=x-1x2-1D.1x-1=-1x-3 答案 1x-1=1•(x+1)(x-1)(x+1)=x+1x2-1.故选:B.