(1) If the inequality | x + 1 | + | X-1 | K holds, the value range of K is obtained School starts the day after tomorrow·········· Better have a little process

(1) If the inequality | x + 1 | + | X-1 | K holds, the value range of K is obtained School starts the day after tomorrow·········· Better have a little process

1.|x+1|+|x-1|=|x+1+1-x|=2
The minimum value on the left is 2
The solution is a nonempty set of real numbers
Then MK
When x = 2, there is | x + 1 | - | X-2 | = 3
And - 1