2(a-5)-(1-4a)=

To simplify the expression \(2(a-5)-(1-4a)\), follow these steps:

1. Distribute the 2 in the first part: \[ 2(a-5) = 2a - 10 \]

2. Distribute the negative sign in the second part: \[ -(1-4a) = -1 + 4a \]

3. Now combine the two results: \[ 2a - 10 - 1 + 4a \]

4. Combine like terms (combine \(2a\) and \(4a\), and combine \(-10\) and \(-1\)): \[ (2a + 4a) + (-10 - 1) = 6a - 11 \]

Therefore, the simplified expression is: \[ \boxed{6a - 11} \]