We have \(\displaystyle x,y\in\mathbb N_0\) and
\[\displaystyle x-y=x^2+xy+y^2\]
The solutions are \(\displaystyle (x_1,y_1),(x_2,y_2),\ldots,(x_n,y_n)\).
Find \(\displaystyle \sum_{i=1}^n(x_i+y_i)\).
by
mathh mathh
