Respuesta :

Create the sum of the given polynomial terms.
f(x,y) = 3x² - 2x²y + 2xy² + 4y² + xy² - y² + 2x²y
        = 3x² + 3xy² + 3y²

Test the given terms to see if they belong in f(x,y).
3:       NO
3x²:   YES
3y²:   YES
3xy²: YES
4x²:   NO

Answer:
The terms in the sum of the given polynomials are 3x², 3y², and 3xy².