Answer:
The average velocity the entire trip was 43.25 mi/h
Step-by-step explanation:
In this case we have to calculate an average based on the miles traveled. First we have to calculate the total of miles traveled, then calculate the portion of the total travel of each and with this calculate the average speed during the trip. First the total miles traveled:

Now the percentages:
At 57 mi/h were 
At 44 mi/h were 
At 37.8 mi/h were 
Now multiplying the speed by the portion and summing them we can have the average velocity:

The average velocity the entire trip was 43.25 mi/h
It looks like the terms are:
(7x2 + 5) and (x - 3)
4.8 pounds, set it up as 4 over ten times x over 12, 4 times 12 divided by ten equals 4.8
The correct graph would be the first one