SOLUTION: This is a cost-revenue word problem. I tried using the form C=Rx+b which just confused me more. A rental company offers two plans. Plan I offers $10 a day and 10 cents a mile, whil

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: This is a cost-revenue word problem. I tried using the form C=Rx+b which just confused me more. A rental company offers two plans. Plan I offers $10 a day and 10 cents a mile, whil      Log On


   



Question 892744: This is a cost-revenue word problem. I tried using the form C=Rx+b which just confused me more. A rental company offers two plans. Plan I offers $10 a day and 10 cents a mile, while Plan II charges 14 cents a day, but no flat fee. If you were to drive 300 miles a day, which plan is better? For what mileage are both rates equal?
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
plan 1 costs 10 dollars a day plus 10 cents a mile.

the formula for plan 1 is c = .10 * 300 + 10 = 40 dollars.

plan 2 costs 0 dollars a day plus 14 cents a mile.

the formula for plan 2 is c = .14 * 300 = 42 dollars.

plan 1 is cheaper because the total cost for plan 1 is 40 dollars while the total cost for plan 2 is 42 dollars.

the formula c = rx + b works but you have to be careful what gets assigned to what.

for plan 1, r = .10 and x = 300 and b = 10
for plan 2, r = .14 and x = 300 and b = 0

note that if you had rented for more than a day, the formula would have had to have been c = rx + by
r would be the cost per mile.
x would be the number of miles.
b would be the cost per day.
y would be the number of days.