化简 (a+3)的绝对值+(a-1)的绝对值 分a≤-3,-3≤a≤1,a>1三种情况 a≤-3 (a+3)的绝对值+(a-1)的绝对值 =-a-3-a+1 =-2a-2 -31 (a+3)的绝对值+(a-1)的绝对值 =a+3+a-1 =2a+2
