-82 - (4 23/30 - 2.55)

First, convert the mixed number 4 23/30 to an improper fraction:
4 * 30 = 120
120 + 23 = 143
So, 4 23/30 is equivalent to 143/30.

Now, subtract 2.55 from 143/30:
143/30 - 2.55 = (143 - 2.55*30) / 30
143 - 76.5 = 66.5
So, 143/30 - 2.55 = 66.5/30

Now, subtract 66.5/30 from -82:
-82 - 66.5/30 = (-82*30 - 66.5) / 30
-2460 - 66.5 = -2526.5

Therefore, the final result is -2526.5.