SOLUTION: there is an error in this problem... can you tell me where it is?? =\ x=2 x(x-1) = 2(x-1) x^2-x = 2x-2 x^2-2x = x-2 x(x-2) = x-2 x=1 Thanks for you help.... jj

Question 149528: there is an error in this problem... can you tell me where it is?? =\
x=2
x(x-1) = 2(x-1)
x^2-x = 2x-2
x^2-2x = x-2
x(x-2) = x-2
x=1
Thanks for you help.... jj
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
It's the second to last step. The error that occurs is a division by zero.

If x=2, then x-2 is really 2-2=0

So

So is really .

In this step, there is a division by to get

However, since , this means that this happens

But you cannot divide by zero. So this is where the flaw occurs. This is a common fallacy in the "proofs" of odd statements like 1=2 or 0=1. Or in this case, you're "proving" that x=1=2.
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