Flipping inequality symbols :D

"Why do we flip the inequality symbol when multiplying by a negative number or solving absolute value inequalities?"

When one has an absolute value inequality, one must switch the inequality symbol when multiplying by a negative number.

> First always remember that only when multiplying or dividing symbols are switched.
>The reason is because if one does not switch the inequality symbol (depending if its negative) it might not be true.
> Also to address a number line one must make sure a switched is performed.

lets try some and see
5 - 3x [>] 20
try -4
5 - 3(-4) [>] 20
5 + 12 [>] 20
17 [>] 20 

*as you can see not true since the symbol wasn't switched

*Here is how it does work.

5 - 3x [>] 20

 Try -4 ( and switch)

5 - 3(-4) [<] 20

5 +12 [<] 20

17 [<] 20

Courtesy of http://www.algebra.com/algebra/homework/Inequalities/Inequalities.faq.question.101178.html