1、如题1/(X+1)>0X>-1 下面你懂的2、|X+2|<3-5<X<1P∪Q=Q1-(a-1)/(x+1)<01<(a-1)/(x+1)(x+1)<(a-1)X-a<-2带入-5<X<1得-3<a<3a>0a=1,2