Editing Negative number (section)

==Negation==
{{main|Additive inverse}}
The negative version of a positive number is referred to as its [[Additive inverse|negation]]. For example, {{math|−3}} is the negation of the positive number {{math|3}}.  The [[addition|sum]] of a number and its negation is equal to zero:
{{block indent | em = 1.5 | text = {{math|1=3 + (−3)  =  0}}. }}
That is, the negation of a positive number is the [[additive inverse]] of the number.

Using [[algebra]], we may write this principle as an [[algebraic identity]]:
{{block indent | em = 1.5 | text = {{math|1=''x'' + (−''x'') =  0}}. }}
This identity holds for any positive number {{math|''x''}}. It can be made to hold for all real numbers by extending the definition of negation to include zero and negative numbers.  Specifically:
* The negation of 0 is 0, and
* The negation of a negative number is the corresponding positive number.
For example, the negation of {{math|−3}} is {{math|+3}}.  In general,
{{block indent | em = 1.5 | text = {{math|1=−(−''x'')  =  ''x''}}. }}

The [[absolute value]] of a number is the non-negative number with the same magnitude. For example, the absolute value of {{math|−3}} and the absolute value of {{math|3}} are both equal to {{math|3}}, and the absolute value of {{math|0}} is {{math|0}}.