## What's the mistake here?

What's the mistake here? hehe

 Recognitions: Science Advisor ##2(a^2-ab) = 1(a^2 - ab)## Therefore either ##2 = 1## or ##a^2 - ab = 0## And ##a^2 -ab## is equal to 0, of course.
 Recognitions: Homework Help Say you wanted to solve the quadratic $x^2=x$. You wouldn't begin by dividing through by x because that assumes $x\neq 0$. If x=0 then you've just lost that solution. In short, dividing by zero is bad.

## What's the mistake here?

Hmm I see... it was stupid from me not realising that.. lol :D

Thanks!

 Recognitions: Homework Help Don't try this at home...
 In the first line, you say a=b and therefore a^2=ab. a^2-ab=0. You are dividing by zero even though it's not defined in mathematics. That's the mistake... :D