Question

You can buy DVDs at a local store fro $15.49 each. You can buy them at an online sore for $13.99 each plus $6 for shipping. How many DVDs can you buy for the same amount at the two stores?

Answer 1

for this problem you need to create two equations;
one that represents the amount of money it would cost to buy a certain amount of movies from the store, and another that shows the money it costs to buy a certain amount of movies online.

Answer 2

d = 15.49 and o = 13.99 + 6?

Answer 3

what you need in those equations is a variable to represent the number of movies

Answer 4

m???

Answer 5

because if I buy 2 movies from the store it will be 2 * $15.49

Answer 6

so lets let x = the number of movies I want to buy and y is the amount of money it costs

Answer 7

if I buy from the store I multiply the number of movies I want to buy times the price of each movie right?

Answer 8

why not m and c?

Answer 9

that works too. m for movies and c for cash?

Answer 10

uhhuh ^^

Answer 11

so the way we can represent the price of movies at the local store is with

15.49m = c

Answer 12

that make sense?

Answer 13

*nods*

Answer 14

now we can make another equation that shows the price of buying movies online. Can you make that one?

Answer 15

i can one sec

Answer 16

13.99m + 6 = c

Answer 17

good

Answer 18

^^

Answer 19

so now the problem asks us how many movies we can buy with the same amount of money at the two stores or for what value of m will both of our equations result in the same number c

Answer 20

hmm can we combine them?

Answer 21

and since 13.99m + 6 = c and 15.49m = c we can set these equations equal to each other because we're assuming c is the same number in both

Answer 22

its like saying 2+2 = 4 and 1 +3 =4 so we can say that 1 + 3 = 2 + 2

Answer 23

29.48m + 6 = c?

Answer 24

oh ota, so 15.49m = 13.99m + 6

Answer 25

yep

Answer 26

^^

Answer 27

can you solve from here?

Answer 28

i think so

Answer 29

let me know what you get

Answer 30

m = 4

Answer 31

yep

Answer 32

61.96 = c

Answer 33

the question didnt ask for that, but yeah good job!

Answer 34

it bothers me if i don't solve for all variables ... sorry