Best Rentals charges a daily fee plus a mileage fee for renting its cars. Barney was charged $123.00 for 3 days and 300 miles, while Mary was charged 226.00 for 5 days and 600 miles. What does Best Rentals charge per day and per mile?

Question

jackellyn · Answer

Let d=charge per day in $ and m=charge per mile in $

Barney: 3d + 300m = 135
Mary:    5d + 600m = 250

You want to solve for d and m
you can do it by substitution or elimination,
can you do that?

anonymous · Answer

yeah i got 4.75 for the charge per mile and 430 for the charge per day which i think is wrong

jackellyn · Answer

i prefer substitution so
lets solve for m in the first eqn
3d + 300m = 135
300m = 135-3d
m= (135-3d)/300
substitute that into the second eqn

5d + 600(135-3d/300) = 250

5d + 270 - 6d = 250
-d + 270 = 250
-d = 250 -270
-d = -20
d=20


Substitute into first eqn

3(20)+300m=135
60 + 300m = 135
300m= 75
m=1/4=0.25

So Best Rentals charges $20 per day and $0.25 per mile.

jackellyn · Answer

Do you understand what I did?
Any parts confuse you?

anonymous · Answer

i usually use eliminated becuase i understand it better but i get what you did