a(3a-2)+(3a-1)(a+5)

To simplify the expression \( a(3a-2) + (3a-1)(a+5) \), we'll break it down step by step.

1. Distribute \( a \) in the first term: \[ a(3a-2) = 3a^2 - 2a \]

2. Distribute \( (3a-1) \) in the second term: \[ (3a-1)(a+5) = 3a \cdot a + 3a \cdot 5 - 1 \cdot a - 1 \cdot 5 \] This simplifies to: \[ 3a^2 + 15a - a - 5 = 3a^2 + 14a - 5 \]

3. Now combine both parts: \[ 3a^2 - 2a + 3a^2 + 14a - 5 \]

4. Combine like terms: \[ (3a^2 + 3a^2) + (-2a + 14a) - 5 = 6a^2 + 12a - 5 \]

Thus, the simplified expression is: \[ \boxed{6a^2 + 12a - 5} \]