Answer:
.25 inches per hour
Step-by-step explanation:
.5 ft
-----------
day
We need to get to inches
1 ft = 12 inches
.5 ft 12 inches
----------- * ------------
day 1 ft
We also need to convert days to minutes
1 day = 24 hours
.5 ft 12 inches 1 day
----------- * ------------ * -------------
day 1 ft 24 hours
6 inches
-------------
24 hours
.25 inches per hour
16a^18 is the answer for what you typed
If the question was ((2a^3)(4a^6)(2a^3))^6, then the answer would be 16a^72.
Look at the picture.
The point-slope form of a line:

We have the points (0, 1) and (2, 0). Substitute:

Answer: 
20$ divided by 8.7 gallons=$2.30
30$ divided by 12.4 gallons=$2.41
Yola got the better deal
D is the correct answer to your question