The additive inverse for a number is its negative value. The sum of an integer and its additive inverse is zero. For the example (5) the additive inverse would be (5)
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The opposite of a number. For example, the additive inverse of 12 is 12.!
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additive inverse: (mathematics) one of a pair of numbers whose sum is zero
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An additive inverse is a number that when added to another equals 0. Source(s) http://en.wikipedia.org/wiki/Additive_inverse.
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