Answer:
87
Step-by-step explanation:
Simplify inside the parentheses:
Cubing is multiplying a number by itself three times. In this case, it is represented by 20³. Expanding helps some, 20 * 20 *20.
20*20 is 400
400*20 is 8000.
20³=8000
1 Gallon because 2 liters are equal to about half a gallon. I hope this helped :D