Then I'd just go on to show you that 8.9 = 9. You haven't actually given a counter example
EDIT: Also there's a flaw in your counter-argument. How can you subtract 1 from 10X to get 9X when you haven't proven X = 1 yet? I can interchange them freely in mine though, but only after I've proven 0.9 = X = 1 already.
