2xy^2 +3x -4y^2 + 2xy^2-3xy^2 -x
Combine like terms
2xy^2+2xy^2-3xy^2 +3x-x -4y^2
xy^2 +2x - 4y^2
xy^2+2x-4y^2
Now let x = -2 and y = -3
(-2) ( -3) ^2 + 2 (-2) -4 ( -3) ^2
(-2) * 9 -4 -4 * 9
-18 -4 - 36
-58
The simplified polynomial is xy^2+2x-4y^2
and when x =-2 and y = -3 the solution is -58