4280 because 75+5+4200= 4280
12.25 just divide all of them first then add all together
a and b are parallel because 114 = 66+48 = 114, these two angles are the same because they are alternate exterior angles, and they couldn't be the same if a and b are not parallel.
Based on the information given the average speed for his trip is 64 miles.
<h3>
Average speed:</h3>
Using this formula
d=rt
r=d/t
Where:
r=rate=?
d=distance=512 miles
t=time=8 hours
Let plug in the formula
r=512/8
r=64 miles
Inconclusion the average speed for his trip is 64 miles.
Learn more about average speed here:brainly.com/question/6504879