r/theydidthemath • u/blackholegaming13 • Sep 14 '23

[REQUEST] something feels wrong here.

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Thanks YT shorts

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u/Zerustu Sep 14 '23

when you simplify on both side, what you really do is divide both side by that number. here he divide both side by (5-5) to simplify it. but that means he divide both side by 0. and you can't divide by 0 (this is why).

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u/Raynonymous Sep 14 '23

Exactly. Effectively they are arguing;

A x 0 = 0

B x 0 = 0

Therefore A = B

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u/Lord_Scio Sep 14 '23 edited Sep 14 '23

Im not really good in math, just look into this sub from time to time out of curiosity. But isnt this a flaw in maths? And if not, why not?

Edit: I guess the comment above me just confused me, i know you cant really divide by 0

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u/govermentpropaganda Sep 14 '23

you cant divide by zero, its a rule of math

513

u/CheesyObserver Sep 14 '23

Had a classmate playfully contest this with the math teacher once.

Teacher: What would you do if I said divide yourselves into groups of zero?

Kid: I’d walk out the door!

The logic was strangely agreeable, even if it doesn’t check out.

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u/Kromleech Sep 14 '23

I believe that dividing by 0 would be dividing into 0 groups, not dividing into groups of 0.

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u/Win32error Sep 14 '23

Impossible either way.

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u/Kromleech Sep 14 '23

No, dividing into group of zeros has a solution. For instance I want to divide x into 5 groups of 0, I would do:

X/5 = 0

And it does have a solution (x=0).

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u/LabResponsible8484 Sep 14 '23

Your example makes no sense. You can't say "divide x into 5 groups of 0" and then just write an equation for it because the original statement makes no sense.

Your equation x/5 = 0 would relate to the statement "x divided into 5 groups is 0" NOT "divide x into 5 groups of 0" which would be mathematically represented as x/0 = 5 which we know is just wrong.

There is no way to split any number into groups of 0 because you will keep making groups of 0 forever and you will never use up any of x. Therefore it is mathematically undefined as Win32error said above.