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Why does the inequality sign have to be flipped when multiplying and dividing by a number like in -2x > 10?

User Joddy
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1 Answer

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Every time we multiply or divide by a negative number on both sides we flip the inequality sign. Lets look at an example

3>2 this is a true statement so even if we multiply the both side by 2 the equation would remain true

3*2>2*2

6>4 so true


So lets look at the equation -2x>10

So divide both sides by -2

-2x/-2>10/-2

x>-5

x<-5

Anytime you divide by a negative number the inequality sign needs to be reversed, in order to keep everything correct we need to reverse the inequality sign

Note: whatever you do to the left side has to be done for the right side too.


User Pranav Kasetti
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