dmezzullo 2 years ago Why must you flip the inequality symbol when you divide by a negative number?

1. dmezzullo

@ParthKohli

2. Raven5

lol really ummm.... just cuz its a rule! haha idk..

3. dmezzullo

That helps alot.

4. Raven5

lol im sorry..... :/

5. izzy56658989

to keep the equation equal i think

6. izzy56658989

does that help??

7. dmezzullo

I wanna get peoples opions first

8. dmezzullo

@SWAG

9. lilkittykat36

You must reverse the sense of inequality because, in essence, you're taking the opposite of both sides. so therfore to keep the equation equal you have to flip the sign.

10. e.cociuba

For the same reason you must flip it when you multiply by a negative number. An example should suffice. 2 < 3 If you multiply by -1, without switching the sign, you get: -2 < -3, which is wrong. Actually, -2 > -3. Look at a number line if you are not sure about this - numbers to the left are less than numbers further to the right. Dividing by a negative number is the same as multiplying by the reciprocal, which in this case is also negative. These signs are strictly the "Greater than" and "Less than" signs. The inequality sign is an = with a / stroke through it. If you divide an inequality by -1 it remains an inequality.

11. e.cociuba

@dmezzullo does tht make sense.

12. siegel

because if you didn't the number would not make sence $-5<-1\times3=-5<-3$ which is correct, but$-5<-1\times3\neq-5\times-1<3$ that would be$5<3$ which is incorrect

13. blarghhonk8

It is to maintain the equality. For example consider the equation: -1 > -2 If you divide or multiply both sides by -1 and DO NOT flip the inequality sign you would then be trying to say 1 > 2 which is obviously not true. Thus you need to flip the inequality sign to ensure the proper answer of 1 < 2

14. thearcane

yeah!!! that's because as bigger is the positive number, smaller will be the negative number

15. Luis_Rivera

Remember that any quality just says if something is greater or smaller than something else. When you multiply or divide a number by negative quantity, the number becomes either negative or positive. In nother words, if it was bigger it becomes smaller, and if it was smaller it become bigger. Therefore, to maintain the inequality true, you must change the direction of the inequality accordingly