The base is 30.
Hopefully I got this correct, not 100%
The first set of expressions bc 3x is equivalent to 3x and -7y is equivalent to -7y
The answer is 15% of $2.55=$0.3825=$0.38 off
Step by step: Take 15% and divide 15% by $2.55 This will give you the amount of money that is going to be added onto the bill. When you divide it and get your answer just add the answer to your original bill.
Answer:

Step-by-step explanation:
V = L*W*H
V= (4/3)*(4/3)*(4/3)
Volume = 
The answer should be number 4