The absolute value of a real number a is defined by the following formula:

| 5 | = 5,    | –5 | = – (–5 ) = 5,     | 0 | = 0. 

Geometric Interpretation
The absolute value of a real number is the distance between the corresponding point on the number line and the zero-point regardless of the direction.
For any numbers  a  and  b, the distance between points  a  and  b  on the number line is  | a – b |.

Absolute values have the following properties:

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