3х+ху^2-х^2у-3у

To simplify the expression 3x + xy^2 - x^2y - 3y, you can factor out common terms:

3x + xy^2 - x^2y - 3y = 3x - 3y + xy^2 - x^2y = 3(x - y) + y(x - y) = (3 + y)(x - y)

So, 3x + xy^2 - x^2y - 3y simplifies to (3 + y)(x - y).