Glossary
Opposite number
The opposite number of \(a\) is the number \(-a\) that gives zero when added to it: \(a + (-a) = 0\). On the number line the opposite number is the same distance from zero, but on the other side.
- The opposite of a positive number is negative, and the opposite of a negative number is positive: \(-(-3) = 3\).
- The opposite of zero is zero itself.
- Subtracting is adding the opposite number: \(a - b = a + (-b)\).
Examples
- E1
What is the value of the expression \(-(-(-7))\)?
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Work from the inside out. \(-(-7) = 7\), so \(-(-(-7)) = -7\). Each minus sign switches sides on the number line, and three switches take you to the opposite side: \(-7\).
Defined in Opposite numbers →
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- FIvastaluku
- SVmotsatt tal
- NBmotsatt tall
- DAmodsat tal
- ISandstæð tala
- ENopposite number