化简
解:原式=
令x+3=0,x-1=0,x-2=0可得x=-3,x=1,x=2.这些点把数轴划分为四个部分:
当x<-3时,原式=-(x+3)-(x-1)+(x-2)=-x-4
当-3≤x≤1时,原式=(x+3)-(x-1)+(x-2)=-x+2
当1<x≤2时,原式=(x+3)+(x-1)+(x-2)=3x
当x>2时,原式=(x+3)+(x-1)-(x-2)=x+4