Answer:
5x^3 + 2x - 2y^3
Step-by-step explanation:
-7x + y^3 + 7x^3 + 6x - 3y^3 - 2x^3 + 3x
group like terms
= 7x^3 - 2x^3 - 7x + 6x +3x + y^3 - 3y^3
add similar elements
= 5x^3 - 7x + 6x + 3x + y^3 - 3y^3
add similar elements
= 5x^3 + 2x + y^3 - 3y^3
add similar elements
= 5x^3 + 2x - 2y^3
