Proposition: Multiplying Negative and Positive Rational Numbers
The multiplication of negative and positive rational numbers follows the following rules:
 A positive rational number times a positive rational number gives a positive rational number, symbolically
\[( + )\cdot ( + )=( + )\]
 A negative rational number times a positive rational number gives a negative rational number.
\[(  )\cdot ( + )=(  )\]
 A negative rational number times a negative rational number gives a positive rational number.
\[(  )\cdot (  )=( + )\]
 Zero times any rational number gives zero.
\[( 0 )\cdot ( \pm )=( 0 )\]
Table of Contents
Proofs: 1
Mentioned in:
Proofs: 1
Thank you to the contributors under CC BYSA 4.0!
 Github:

References
Bibliography
 Piotrowski, Andreas: Own Research, 2014