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

First, let's simplify the expression inside the parentheses:
-(-9/11 + 3/2) = -(-15/22) = 15/22

Now, let's substitute this back into the original expression:
6/5.7/4 - 15/22 : 13/44

Next, let's simplify the division:
6/5.7/4 = 6/(5.7/4) = 6 * (4/5.7) = 6 * 0.701754 = 4.210526

Now, let's substitute this back into the expression:
4.210526 - 15/22 : 13/44

Now, let's simplify the division:
15/22 : 13/44 = (15/22) * (44/13) = 60/13

Now, let's substitute this back into the expression:
4.210526 - 60/13

To subtract these fractions, we need to find a common denominator, which is 13:
4.210526 = 4.210526 * 13/13 = 54.736842 / 13

Now, let's subtract the fractions:
54.736842 - 60 = -5.263158

Therefore, the final answer is -5.263158.