m(x-1)=3(x+2）mx-m=3x+6(m-3)x=6+m若m-3=0，即m=3则原方程无解m-3≠0时x=(6+m)/(m-3)解为正数则(6+m)/(m-3)>0则m>3或m<-6解为负数则(6+m)/(m-3)<0则-6
x>3或x<-6 -6
