Algebra 1: Common Core (15th Edition)

$23x^2y-8x^2y^2-4x^3y^2-9xy^2$
Combine like terms to simplify: $12x^2y-8x^2y^2+11x^2y-4x^3y^2-9xy^2$ $=12x^2y+11x^2y-8x^2y^2-4x^3y^2-9xy^2$ $=(12+11)x^2y-8x^2y^2-4x^3y^2-9xy^2$ $=23x^2y-8x^2y^2-4x^3y^2-9xy^2$