Consider the expression 
Use main properties for powers:
1. 
2. 
3. 
Then

The result in scientific notation is 
The result as a decimal is 
Answer:
3.5
Step-by-step explanation:
If you multiply 3.5 for example by 2 (which is the number of gallons) you get 7 which is the cost (also a proportional relationship).
Answer: 200
Because for each minute it goes up 200 more.
Answer:
C. r = d/2
Step-by-step explanation:
The radius is half of the diameter.
The diameter divided by 2 would equal the radius of a circle.