Am I a retard or is 1=/=.999...

I dont get the supposed proofs like:
0.999...=x
9.999...=10x
9=9x
1=x
It doesnt make sense to me because shouldn't 9.999... have a zero on the end to actually make it 10 times bigger otherwise it wouln't be right?
or:
9.999...=9/10^0+9/10^1+9/10^2+9/10^3...9/10^n...
and if u subract with 0.999...=9/10^1+9/10^2+9/10^3...9/10^n... you then get:
9/10^0 -0.9/10^0 + 9/10^1 -0.9/10^1 + 9/10^2 -0.9/10^2 + 9/10^3 -0.9/10^3 ... 9/10^n -0.9/10^n ...=8.1/10^0 + 8.1/10^1 + 8.1/10^2 + 8.1/10^3 ... 8.1/10^n ...=8.999...

Too say that 0.999...=1 is just a presumption right?