(4у3+15у) - (17у-у3)

To simplify the expression \( (4y^3 + 15y) - (17y - y^3) \), follow these steps:

1. Distribute the negative sign across the second set of parentheses:

\[ 4y^3 + 15y - 17y + y^3 \]

2. Combine like terms. First, combine the \( y^3 \) terms:

\[ 4y^3 + y^3 = 5y^3 \]

Next, combine the \( y \) terms:

\[ 15y - 17y = -2y \]

3. The final simplified expression is:

\[ 5y^3 - 2y \]

So, \( (4y^3 + 15y) - (17y - y^3) = 5y^3 - 2y \).