(-3-y)² + y²

To simplify the expression (-3 - y)² + y², we will first expand (-3 - y)² and then combine like terms.

The expression (-3 - y)² is equal to: (-3 - y) * (-3 - y)

Let's expand it using the FOIL method (First, Outer, Inner, Last): = (-3 * -3) + (-3 * -y) + (-y * -3) + (-y * -y) = 9 + 3y + 3y + y² = 9 + 6y + y²

Now, let's combine this with the original y² term: = 9 + 6y + y² + y² = 9 + 6y + 2y²

The simplified form of (-3 - y)² + y² is 2y² + 6y + 9.