SOLUTION: why does the inequality sign change when both sides are multiplied by a negative number. Does this happen with equations, why or why not?

Question 606090: why does the inequality sign change when both sides are multiplied by a negative number. Does this happen with equations, why or why not?

Found 2 solutions by richard1234, stanbon:
Answer by richard1234(7193) (Show Source): You can put this solution on YOUR website!
Suppose . Subtracting a+b from both sides does not change the inequality sign:

For example, 3 < 7 but -3 > -7. This does not happen with equations (you can't "flip" an equal sign as you flip an inequality sign).
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
why does the inequality sign change when both sides are multiplied by a negative number.
-------
2 < 3 means 3 is to the right of 2 on the number scale.
-----
Multiplying by -1 flips the relationship of the numbers over
the y-axis so -3 is to the left of -2, i.e. -3 < -2
-----
Does this happen with equations, why or why not?
No; 2 = 2 and -2=-2

----------------------
Cheers,
Stan H.
==================
RELATED QUESTIONS
Why does the inequality sign change when both sides are multiplied or divided by a... (answered by mangopeeler07)
Why does the inequality sign change when both sides are multiplied or divided by a... (answered by kitkat2009)
Why does the inequality sign change when both sides are divided and multiplied by a... (answered by stanbon)
Why does the inequality sign change when both sides are multiplied or divided by a... (answered by rapaljer)
why does the inequality sign change when both sides are multiplied or divided by a... (answered by solver91311,Edwin McCravy)
Why does the inequality sign change when both sides are multiplied or divided by a... (answered by solver91311)
why does the inequality sign change when both signs are multiplied or divided by a... (answered by dewasmaharaja)
Why does the inequality sign change when both sides are multiplied or divided by a... (answered by stanbon)
The original question was: "Why does the inequality sign change when both sides are... (answered by kmcruz09)