billy was doing maths. He proceeded as follows,
Let, a=b
Multiplying both the sides with a, he got, a2=ab
Subtracting b2, from both the sides, he got, a2- b2= ab- b2
Now, a2- b2 = (a+b)(a-b)
So, (a+b)(a-b)= ab- b2
Taking b as common, (a+b)(a-b)=b(a-b)
Now, cancelling the common term (a-b), he got, (a+b)=b
Now the magic, as a=b (taken), if he takes a=b=1 then 1+1=1 or 2=1!
Let, a=b
Multiplying both the sides with a, he got, a2=ab
Subtracting b2, from both the sides, he got, a2- b2= ab- b2
Now, a2- b2 = (a+b)(a-b)
So, (a+b)(a-b)= ab- b2
Taking b as common, (a+b)(a-b)=b(a-b)
Now, cancelling the common term (a-b), he got, (a+b)=b
Now the magic, as a=b (taken), if he takes a=b=1 then 1+1=1 or 2=1!
