In order to simplify this expression, we need to add the like terms.
Before that, since there is a minus sign between the parenthesis, we need to change the signal of every term on the second parenthesis:
[tex]\begin{gathered} \left(2xy^2+5x^2y-y\right)-(-3x^2y-4xy^2+6y)\\ \\ =2xy^2+5x^2y-y+3x^2y+4xy^2-6y\\ \\ =(2xy^2+4xy^2)+(5x^2y+3x^2y)+(-y-6y)\\ \\ =6xy^2+8x^2y-7y \end{gathered}[/tex]Therefore the final expression is 6xy² + 8x²y - 7y.
