d) \( 2 x y+x y^{2}-x^{2} y-2 x y^{2}-y x \)

Let’s simplify the expression \( 2xy + xy^2 - x^2y - 2xy^2 - yx \). First, we'll combine like terms: 1. Start with the terms involving \( xy \): \( 2xy - yx \) simplifies to \( xy \). 2. Next, for terms involving \( xy^2 \): \( xy^2 - 2xy^2 \) simplifies to \(- xy^2\). 3. Finally, we retain the term \(-x^2y\). Putting it all together, we get: \[ xy - x^2y - xy^2 = y(x - x^2 - xy) \] So the simplified form of the expression is: \[ y(x - x^2 - xy) \]