Respuesta :

Combine like terms.

-14cd + 15cd - 15cd = -14cd
-2c²d² + 9c²d² = 7c²d²

7c²d² - 14cd is your answer

hope this helps
-14cd - 2c²d² + 15cd+9c²d²-15cd
= cd(-14 + 15 - 15)  + c²d²(-2 + 9)
7c²d² -  14cd

Hope it helps