d = days rented for
m = miles driven for
so the cost of the car is 35 bucks a day and 45 cents or $0.45 per mile driven, let's check it out for say a few days
1st day, 3 miles......................35(1) + 0.45(3)
2nd day, 2 miles..................35(2) + 0.45(2)
3rd day, say 5 miles............35(3) + 0.45(5)
dth day, and m miles..........35d + 0.45m
so the cost function could be written as C = 35d+0.45m.
now, we know for 2 days, d = 2, it cost 166.75 bucks, so
Answer:
Jennifer would complete the job on her own in 5 hours.
Step-by-step explanation:
Solving a quadratic equation:
Given a second order polynomial expressed by the following equation:
.
This polynomial has roots such that
, given by the following formulas:
Rates
The together rate is the sum of their separates rate.
We have that:
Jennifer takes x hours to complete the job on her own, so her rate is 1/x.
Carl needs 15 hours longer than Jennifer, that is, 15 + x hours, so his rate is 1/(15+x).
The together rate is 1/4. So
Applying cross multiplication.
Quadratic equation with . So
Since the time to complete the job has to be a positive value.
Jennifer would complete the job on her own in 5 hours.