Comments on From Diophantus to Fermat

Sivasubramaniam Sivakumar said:

Nice!

I would never thought of this:

This is of the form \( 2(3a^2b + b^3) \) where \( a = y \) and \( b = 3. \) Now \( 2(3a^2b + b^3) = (a + b)^3 - (a - b)^3. \)