The given expression "1,65:0,35" appears to be a ratio.

To simplify the ratio, we can divide both numbers by their greatest common divisor (GCD).

The GCD of 165 and 35 is 5.

Dividing both numbers by 5, we get:

165 ÷ 5 = 33
35 ÷ 5 = 7

Therefore, the simplified ratio is 33:7.