0,4-(а-5,5)

To simplify the expression \(0.4 - (a - 5.5)\), we follow these steps:

1. Distribute the negative sign across the parentheses: \[ 0.4 - a + 5.5 \]

2. Combine like terms: \[ 0.4 + 5.5 - a = 5.9 - a \]

So, the simplified expression is: \[ 5.9 - a \]