Please explain via graphs and/or algebra

## Why do you have to reverse inequality signs when you divide or multiply both sides of the inequality by a negative number?

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# 1 Answer

-2 < -1

Multiply both sides by -1,

2 > 1

Reason: When you multiply both sides by -1, the order on number line from left to right of the numbers reversed.

a ... b becomes -b ... -a.