4y3 - 17 + 5y2 + (12 ÷ 3)

To simplify the expression:

4y^3 - 17 + 5y^2 + (12 ÷ 3)

First, simplify the division inside the parentheses:

4y^3 - 17 + 5y^2 + 4

Now, combine like terms:

4y^3 + 5y^2 - 13