$\text { Let } f ( x , y ) = x ^ { 2 } y + y ^ { 2 } x + 2 x y \text {. Find }$

Short Answer

$\text { Let } f ( x , y ) = x ^ { 2 } y + y ^ { 2 } x + 2 x y \text {. Find }$
Enter just a polynomial in x plus or minus a polynomial in y plus or minus two, both polynomials in standard form (no label, no parentheses).