Answer:
5x^3 - 2x^2 + 2
Step-by-step explanation:
First, distribute the addition sign to get rid of the parentheses
2x^2 +4 -x^3 -4x^2 +6x^3 -2
then combine like terms
-2x^2 +2 +5x^3
then order them in deacreaing power of x