Question

A company rents cars at $40 a day and 15 cents a mile. Its competitor's cars are $50 a day and 10 cents a mile.

a. For each company, give a formula for the cost of renting a car for a day as a function of the distance traveled.

b. On the same axes, graph both functions.

c. Decide which company is cheaper.

***Not really sure how to start this off! @jim_thompson5910 :)

Answer 1

Start off by defining variables

Answer 2

So how many variables will we need?

Answer 3

umm 2? one for days and one for miles?

Answer 4

close, but no

Answer 5

one for miles, yes

but you don't need one for days

Answer 6

Let

x = number of miles
y = total cost (for the entire day)

Answer 7

ohhh okay i see... so we need to come up with 2 equations right? one for company a and one for company b?

Answer 8

For the first company, it says that it "rents cars at $40 a day and 15 cents a mile"

So what is the equation?

Answer 9

40x+15y ?

Answer 10

what is y again?

Answer 11

ohhh oops...

so y=40+15x ?

Answer 12

closer

Answer 13

it's not $15 a mile though

Answer 14

oh right!

y=40+0.15x ?

Answer 15

good

Answer 16

now find the other equation

Answer 17

yay!

okay would the other one be

y=50+0.10x ?

Answer 18

correct

Answer 19

awesome! :) so are we done with part a?

Answer 20

yep, now onto part b

Answer 21

okay, so that's graphing both of those equations?

Answer 22

yes

Answer 23

on the same axis

Answer 24

okay, soooo for company one, it should hit the y axis at 40 right?

but how do I graph the 0.15x part? :/

Answer 25

0.15 is the slope

0.15 = 15/100 = 3/20

Answer 26

ohh okay... so it'd be something like this? did I graph that correctly?