To solve this problem, we need to follow the order of operations (parentheses, exponents, multiplication and division from left to right, addition and subtraction from left to right).

0.09 + 3.61 = 3.701/5 - 18.63 = -18.00(2 1/2 - 1.805) = (5/2 - 1.805) = (2.5 - 1.805) = 0.6950.695 / 1.39 = 0.54 / 2.5 = 1.6

Now, let's put it all together:

3.70 - 18.00 = -14.30
-14.30 / 0.5 = -28.60
-28.60 + 1.6 = -27

Therefore, the final solution is -27.