
Originally Posted by
Mittopotahis
alright, let's let x = .999999...
x = .999999...
I trust everyone agrees that if we times it by 10, we're gonna get 9.999999...
10x = 9.999999...
Now we'll find 9x. To do that, we just simply take 10x, and minus 1x.
10x - x = 9.999999 - .999999
9x = 9.
Divide both sides by 9 to find x by itself...
9x/9 = 9/9
x = 1
If we remember back to the start, we let .999999... equal x. So lets substitute that back in. x = .999999...
.999999... = 1.
And there you have it. .999999... DOES equal 1. Solid mathematical proof.