SOLUTION: Twice last month, Judy Carter rented a car from Enterprise in Fresno, California, and traveled around the southwest on business. Enterprise rents its cars for a daily fee, plus an

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Twice last month, Judy Carter rented a car from Enterprise in Fresno, California, and traveled around the southwest on business. Enterprise rents its cars for a daily fee, plus an       Log On


   



Question 520665: Twice last month, Judy Carter rented a car from Enterprise in Fresno, California, and traveled around the southwest on business. Enterprise rents its cars for a daily fee, plus an additional charge per mile driven. Judy recalls that her first trip lasted 4 days, she drove 450 miles, and the rental cost her $240.50. One her second business trip she drove 200 miles in 3 days, and paid $146.00 for the rental. Fnd the daily fee and the mileage charge.
I get so confused in all these numbers. How do I set up my equation?

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let d = daily fee in dollars
Let +m = milage charge in dollars
In words:
( Cost of rental ) = ( number of days rented )x( daily fee ) + ( miles driven )x( milage fee )
For her first trip:
(1) +240.5+=+4d+%2B+450m+
For her 2nd trip:
(2) +146+=+3d+%2B+200m+
-------------------------
Multiply both sides of (1) by +3+
Multiply both sides of (2) by +4+,
Then subtract (2) from (1)
(1) +721.5+=+12d+%2B+1350m+
(2) +-584+=+-12d+-+800m+
+137.5+=+550m+
+m+=+.25+
and, since
(2) +146+=+3d+%2B+200m+
(2) +146+=+3d+%2B+200%2A.25+
(2) +146+=+3d+%2B+50+
(2) +3d+=96+
(2) +d+=+32+
The rental cost is $32/day and $.25/mile
check answer:
(1) +240.5+=+4d+%2B+450m+
(1) +240.5+=+4%2A32+%2B+450%2A.25+
(1) +240.5+=+128+%2B+112.5+
(1) +240.5+=+240.5+
OK