In mathematics, the opposite or additive inverse of a number is a number which, when added to , results in 0. The opposite of is .[1][2] For example, −7 is the opposite of 7, because .
A number is called an opposite number of another number if . By definition, is the opposite number of . For example, is the opposite number of and vice-versa. This is because
Opposite numbers are also known as additive inverses.
The opposite numbers satisfy the properties listed below.[3]