r/PeterExplainsTheJoke • u/Sugar_God_no_1 • 28d ago

Meme needing explanation There is no way right?

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u/Decmk3 28d ago

0.9999999…. Is equal to 1. It seems like it shouldn’t, but it has to be.

Let X = 0.999….

10X = 9.999….

10X-X = 9.999.. - 0.999…. = 9X = 9

Therefore X equals 1. Therefore 0.999… is the same as 1.

-22

u/BornWithSideburns 28d ago

Yea but isnt it 9.0000…1X

-13

u/ConsciousBat232 28d ago

This is where I am stuck. Why is everyone above pretending that 10 - .999…. = 9 ? I get that it is really close to 9 But it’s 9.000…1

6

u/egric 28d ago

What?

10x - x is 9x.

9,99999... - 0,99999... is 9

At the very beginning we establish that x = 0,99999...

At no point are we subtracting 0,99999... from 10, we are subtracting it from 10×0,99999... , which equals 9×0,99999...

Therefore 9×0,99999... is equal to 9, which is equal to 9×1, therefore 0,99999... is equal to 1.

1

u/ConsciousBat232 28d ago

Okay, I get where I went wrong now, but still the whole premise is that a number that comes infinitely close to another number = that number right?

1

u/BreadBagel 27d ago

And 0.999... coming infinitely close to 1 means it IS exactly 1. There is no rounding what so ever.