X doesn't dissapear, you forgot to divide 9 by x.

eh it's late. I even thought of it when I read through the post but forgot to include it in the reply.

But what if x = 0?  :D

No, it is the standard procedure for solving equations. Remember, as long as you do the same thing on both sides of the equal sign, then, well, both sides are still equal.

If we were to do it the way you suggest we would get:

10x=9+x

10x/x=9/x+x/x

10=9/x+1

etc.

And you could get the same result, but you'd do a lot of unnecessary shit to get there. Also, how do you remove that 1 on the right side?

(You subtract 1 on both sides, same as I did, except I subtracted x on both sides )

oh no , i will have nightmares for remembering this , we studied this one in algebra in preparation school to become an engenieer , and it was my worst years loool

For some reason I dont like it...

Because your still missing that 0.000000000..... 01 if you go infinity far out to reach it.
But I can understand in the practical world, 0.99999 ect = 1.

There wouldnt ever be a practical time, where 0.999 infinity far out, wasnt ever the same as 1.
Because our real world doesnt work that way, theres nothing infinite in it.

This is like when you divide by infinity, and which side of numbers you come from... its weird stuff :p

Don't see what's supposed to be so mindboggling about the concept, seems trivial enough...

You are a bit too late. Watch this 4 year old vid to see the sad truth.

I think people just don't understand infinity well enough. Look up Hilbert's Hotel, should make it more comprehensible.

The thing is 0.99  is differnt than 1.

you use a 0 and a 9, when you write 0.9999999999 ect,

but you use a 1 when you write 1.

thus 0.999999 infinity out, shouldnt be the same as 1.

In a perfect world where you could go infinity out, and see infinity they shouldnt be the same.

This proof shows that they are the same.

Dispite you writeing them differntly.   0.999 = 1.