Simplify the expression:

To simplify the expression \(5y + 5y - 4y - 2y\), you can combine like terms:

1. First, combine \(5y + 5y\): \[ 5y + 5y = 10y \]

2. Next, combine \(10y - 4y\): \[ 10y - 4y = 6y \]

3. Then, combine \(6y - 2y\): \[ 6y - 2y = 4y \]

Putting it all together, the simplified expression is: \[ \boxed{4y} \]