10th grade polynomials, algebra. I'm asking for a friend. (literally) Image below of it. 
 
											 
											Answer:
3y5 + 8y4 – 8y3
Step-by-step explanation:
2y5 – 6y3 + 1 + y5 + 8y4 – 2y3 – 1
2y5 + y5 + 8y4 – 6y3 – 2y3 + 1 – 1
3y5 + 8y4 – 8y3