let a=b

a^2=ab

a^2-b^2=ab-b^2

(a+b)(a-b)=b(a-b)

a+b=b

2b=b

2=1

This series of equations is given to prove that 2=1.Although this may appear correct there is a fallacy in this.At step 5 both sides have been divided by a-b.But a=b.So a-b=o.An d, no number can be divided by 0.

## Comments

Sort by:

TopNewesti found a solution when we compare 1=2 with a=b => a is not equal to b thats it any doubts reply me ill say – Sudoku Subbu · 2 years ago

Log in to reply

I had given the solution that it is incorrect.Then how can you give a solution for a incorrect question– Vishal S · 2 years agoLog in to reply

– Sudoku Subbu · 2 years ago

that's what iam saying a is not = b you considered a wrong equation in the beggeningLog in to reply

How can you tell that \(a \neq b\).I had provided the word let a=b.If a=b in the above series of equation, we get 1=2– Vishal S · 2 years agoLog in to reply

We had that too in a quiz after we discussed trigonometric ratios :D The questions was "Prove that 2=1" I kept going to 1=0 until we were given a hint - difference of two squares :D – Marc Vince Casimiro · 2 years ago

Log in to reply