CEVAP:

For a given real number a on the real line, the distance from a to the origin is called the absolute value of a and is denoted by |a|. The absolute value has the following properties:
|a| ? 0, |a + b| ? |a| + |b|, |a . b| = |a| .|b|, |a / b| = (|a|) / (|b|) (b?0) .
Open and closed finite intervals can be represented by using the absolute value.