Use three 5s and no other digits to make an expression that equals 6.

You can use these only:

parentheses, +, -, /, *, regular factorial sign, square root symbol (or "sqrt"), decimal point (no repeating decimal use), concatenation of digits

I'll start if off:

5 + 5/5 = 6

I am looking for at least three other primitive* solutions.

* For example, "5/5 + 5 = 6" would not be another primitive solution.