Please solve the question in the photo.

Answer:
2x^3 +7x^2+3x-2
Step-by-step explanation:
3x^3 +7x^2 -x
- ( x^3 -4x +2)
------------------------
The first step is to line up the variables by degree
3x^3 +7x^2 -x
- ( x^3 -4x +2)
----------------------------
Then distribute the minus sign
3x^3 +7x^2 -x
- x^3 +4x -2
----------------------------
2x^3 +7x^2+3x-2