Answer:
y = -3 or 1
Step-by-step explanation:
In order to solve the polynomials, you need to add them and then factor:
5y - 2y² + 9 + 3y² - 12 - 3y
Combine like terms: y² + 2y - 3
Factor: (y + 3)(y - 1)
Solve for y: y + 3 = 0 and y - 1 = 0 or y = -3 or 1
