Question 946347
A car travel for a total of 14 hours.
 The car averages 70 miles per hour for y hours and averages 55 miles per hour for the rest of the time.
 Express the total distance traveled by the car in terms of y.
:
From the information given, we know
Car 1 averaged 70 mph for y hrs
then, since the total travel time is 14 hrs,
car 2 averages 55 mph for (14-y) hrs
:
dist = speed * time
:
d(y) = 70y + 55(14-y)
d(y) = 70y + 770 - 55y
d(y) = 70y - 55y + 770
d(y) = 15y + 770