-8.25 - 3.72 + (-1/30 + 7/30)

First, simplify the fractions inside the parentheses:

-1/30 + 7/30 = 6/30 = 1/5

Now, substitute this value back into the equation:

-8.25 - 3.72 + 1/5

Next, combine the integer values:

-8.25 - 3.72 = -12.97

Finally, add the fraction to the sum:

-12.97 + 1/5

Converting the decimal to a fraction:

-12.97 = -1297/100

Adding the fractions:

-1297/100 + 1/5 = -1297/100 + 20/100 = (-1297 + 20) / 100 = -1277 / 100

So, the final answer is -1277/100.