Answer:
4x^3 + 5
Step-by-step explanation:
(6x^3 - 4) + (-2x^3 + 9)
You can get rid of the parentheses
6x^3 - 4 + -2x^3 + 9
Combine like terms
6x^3 + -2x^3 = 4x^3
-4 + 9 = 5
