Difference between revisions of "Proof that 2=1"

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Wait, What?
 
Wait, What?
 
The error is dividing by (a-b). (a-b) is 0, so this proof divides by 0.
 
Dividing by 0 is illegal. Thus, this proof is false.
 

Revision as of 19:54, 27 June 2019

1) $a = b$. Given.

2) $a^2 = ab$. Multiply both sides by a.

3) $a^2-b^2 = ab-b^2$. Subtract $b^2$ from both sides.

4) $(a+b)(a-b) = b(a-b)$. Factor both sides.

5) $(a+b) = b$. Divide both sides by $(a-b)$

6) $a+a = a$. Substitute $a$ for $b$.

7) $2a = a$. Addition.

8) $2 = 1$. Divide both sides by $a$.

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