解:零点分区,零点为1,51.当x<1.-x+1-x+5<7,得x>-1/2,故-1/22.当1≤x≤5.x-1-x+5<7,得4<7,成立,故1≤x≤53.当x>5,x-1+x-5<7得x<13/2 即5综上知解集为-1/2
