x^2 + y^2 = 2(x+y) + xy
what are all the possible solutions (x,y) if x and y are both integers?
This may be a little difficult to solve algebraically [ although there may be a way to do so ]
Look at the graph here : https://www.desmos.com/calculator/oznsn0uwpe
Because of the presence of the xy term, we have a rotated conic (ellipse??)
We are looking for all the lattice points (points with integer coordinates ) that this graph passes through
They are the same ones I enumerated in my previous answer.......