Let a = b
So a-b =0 (bringing b on the left side)
Multiply LHS by 2
the result would be
2a-2b=0
Since a-b=0
replace 0 with a-b
i.e. 2a-2b = a-b
nest step
2(a-B) = a-b
Divide both sides by a-b
2(a-B)/(a-B) = (a-B)/(a-B)
final result
2=1
Edit: Added [ code ] tags to keep smileys making the math illegible - Zone