Answer:
A) y ^4 − 13 y^ 3 − 6 y
Explanation:
4y^4 - 8y^3
- 5y^3 + 6y + 3y^4
----------------------------
flip the equations around
-8y^3 + 4y^4
- 5y^3 + 6y + 3y^4
------------------------
-13y^3 - 6y + y^4
Rearrange to get:
y^4 - 13y^3 - 6y
I hope this helps you out!!!