You should KNOW 

        1.  How to solve simple and compound (linear) inequalities and express the solution set using inequalities, interval notation, and real line sketches. 
        2.  What "absolute value" means, and how to translate an inequality using absolute value into a compound inequality. 
        3.  That the geometric meaning of |x - y| is that  |x - y| is the distance between the numbers  x  and  y  on the number line. 

You should be ABLE TO

         1.  Solve simple and compound inequalities and express the solution set in various ways.
          2.  Solve inequalities that involve absolute value by algebraic methods and by the geometric interpretation in 3. above when possible.