The rules for removing the absolute value bars in inequalities
are

1.  can be rewritten as 

2.  can be rewritten as 

3.  can be rewritten as 

4.  can be rewritten as 

Your problem:


is case 4.

 

can be rewritten as



Add  to both sides in both parts:



      

<==========@-----------------------@=========>
 -9 -8 -7 -6 -5 -4 -3 -2 -1  0  1  2  3  4  5

   

Edwin