And I can prove it to you if you don't see the logic to begin with
There are many proofs but I will start out with this one:
X = 0,999...(infinite 9s)
We multiply with 10 on each side:
(and yes you can do that, because it's not the number that is infinite it is the trails of 9s)
10X = 9,999... (infinite 9s)
We etract 1 X on each side:
10X - X = 9.999... - 0,999...
9X = 9
We devide on both sides with 9
9X/9 = 9/9
X = 1
There you have it.
So what does GFY think does 0,999... = 1?