-(-3y-a)+(-a+2y)

To simplify the expression \(-(-3y-a)+(-a+2y)\), follow these steps:

1. Distribute the negative sign in the first part of the expression: \[ -(-3y-a) = 3y + a \]

2. Rewrite the expression with the distributed terms: \[ 3y + a + (-a + 2y) \]

3. Combine like terms:

   • Combine \(a\) and \(-a\): \[ a - a = 0 \]
   • Combine \(3y\) and \(2y\): \[ 3y + 2y = 5y \]

4. Now, the simplified expression is: \[ 5y + 0 = 5y \]

Thus, the simplified form of \(-(-3y-a)+(-a+2y)\) is: \[ 5y \]