Implied Parenthesis...

[arcenite]

I thought this thread was about the comment I made in the other thread...hah. I was truly never taught that multiplication and division are read left to right. Could potentially explain why I had so much trouble with my engineering classes!

 

[Brigandier]

As for .999 repeating:

Let x = .99999...
10x = 9.9999...

10x-x=9
10x-x=9x
9x=9
x=1

Done.

That said, I seriously doubt I'm the only one here who could prove those, though, I may be the only one who'd bother actually doing so =p

10x-x=9 and 10x-x=9x? That's f'ed up, man.

 

[Schfifty Five]

i wanted to make fun of the wrong people in another thread.

yeah all those 288 people are retards.

 

[Schfifty Five]

10x-x=9 and 10x-x=9x? That's f'ed up, man.

if X = 1, then that's valid.

 

[PlasmaBomb]

I love "implied perenthesis" because then i can create whatever answer i want to an Algebra equation I can never be wrong. Fear me!!!

It will not stop your probe from crashing into Mars...

 

[IronWing]

Holy Buttercups! I earned an Urban Dictionary entry?!?!?

 

[Brigandier]

if X = 1, then that's valid.

But isn't that already assuming .9bar =1? That's not a proof

 

[PlasmaBomb]

But isn't that already assuming .9bar =1? That's not a proof

Where does it even mention 0.9 = 1 ?!?

 

[Brigandier]

Where does it even mention 0.9 = 1 ?!?

Read what he wrote, man. Assume x=.9bar, then he does his equations and somehow gets 10x-x=9 and 10x-x=9x, which is f'd up, because that only works if x already equals 1. Then he comes to x=1, surprise! That's what I call republican math.

 

[PlasmaBomb]

Read what he wrote, man. Assume x=.9bar, then he does his equations and somehow gets 10x-x=9 and 10x-x=9x, which is f'd up, because that only works if x already equals 1. Then he comes to x=1, surprise! That's what I call republican math.

I just came from the garage... the thread had been using 0.999... to represent 0.999..., but yes you could use

  _
0.9

using the term "bar" threw me... it's late.

To be fair the equation doesn't need the line 10x -x = 9x...(typo?)

10x - x = 9 is sufficient if you solve -

9x = 9
x = 1

So 0.999... = 1

 

[Brigandier]

I recant what I said, .9bar equals 1.

 

[Brigandier]

I just came from the garage... the thread had been using 0.999... to represent 0.999..., but yes you could use

  _
0.9

using the term "bar" threw me... it's late.

To be fair the equation doesn't need the line 10x -x = 9x...(typo?)

10x - x = 9 is sufficient if you solve -

9x = 9
x = 1

So 0.999... = 1

I sat down to poop, and that popped in my head.

 

[ircLimerick]

@Patterner Heh, actually, this is my first time on these forums at all, thoooough, I might have stumbled across them at some point. I came across this particular post when I was looking at a facebook poll that seems to have gained some popularity for 6/2(1+2) being 1 or 9. Some of you probably have seen it =p

And @Everyone else...

I have to admit, I'm a bit lost as to where you lost me.

Let x = .9999....
Then, to multiply by 10, you shift the decimal over 1 place.
Multiplying both sides by 10...

10x=9.999....
Now we go back to the original, x = .9999...
10x - x = 9.999... - .9999...
We are here simply subtracting x from both sides of the above equation.
Simplifying...
9x = 9 by simply performing the subtraction.
Dividing by 9... we're getting x = 1. QED.

There is no assumption at any point that x=1.

This proof is pretty well accepted in the mathematical community as a whole. The only legitimate objection I've seen, which, I have to lean some validity to is whether 9.999... - .9999.... legitmately can be said to equal 9. It's argued that because the numbers are infinite, the same number of 9's is to the right of both, making it valid. I personally find the step questionable, but there you have it =p

@Plasma:

10x-x=9
10x-x=9x <--- This was just the simplification of the left hand side of the above equation (If you have 10 x and take away 1 x, how many x do you have?); no, I may not have had to explicitly state it. And now I see this is the step that people got lost on. This is not a simplification of the whole equation above, only the actual performance of the subtraction of the left hand side of the equation

9x=9
x=1