Find the error in this Algebra Problem, 2=1

[Porkbutts]

lol, i think its a nifty problem, i didn't notice it at first. If you know the answer, don't tell any1 =).

Let a=x
a = x
a+a = a+x
2a = a+x
2a-2x = a+x-2x
2(a-x) = (a-x)
2 = 1