To solve this expression, we need to follow the order of operations (PEMDAS):

First, we simplify the expression inside the parentheses:

4/9 - 6/5 = (20/45) - (54/45) = -34/45

Next, we substitute this back into the original expression:

3•1,5 - (-34/45) : 1 8/9

Now we multiply 3 by 1.5:

3•1.5 = 4.5

Finally, we divide 4.5 by 1 8/9:

To divide 4.5 by 1 8/9, we can first convert 1 8/9 to an improper fraction:

1 8/9 = (9*1 + 8)/9 = 17/9

Now we divide 4.5 by 17/9:

4.5 ÷ 17/9 = 4.5 * 9/17 = 40.5/17 = 2.38235

Therefore, the solution to the expression is approximately 2.38235.