Question

How do I find the price of a cd if 3 cd + 2 DVD=$67. And 2cd+4dvd=$90 ?

Answer 1

looks to me like you will have to set up a system of equations and use either the elimination methode or the subtution methode to solve this problem

Answer 2

zbay is exactly correct. But if you have a graphing calculator, you could set up a matrix.

Answer 3

I set up a graph but got stuck

Answer 4

do it this way
3c+2d=67
2c+4d=90

Answer 5

there is your system of equations

Answer 6

I tried that too but got stuck

Answer 7

Ok where did you get stuck at?
and what methode were you trying?

Answer 8

I tried both. I set up a chart but sine the two are not right next to each other on the chart I got stuck.

Answer 9

Oh it's been a while for me but lets try this together

Answer 10

Ok!

Answer 11

Ok, first we want to pick a varible and make it an oppisite inverse of the other equation
i am going to do this by multiplying the top function by -2

Answer 12

(-2)(3c+2d=67) -6c-4d=-134

Answer 13

Do u know how to do it using a graph? Btw thanks for all your help.

Answer 14

-6c-4d=-134
2c+4d=90
No i don't think i know how to do the graph

Answer 15

Ok that is fine

Answer 16

when we combine them we get (-4c=-44)

Answer 17

d= 11

Answer 18

Your awesome ,,, thanks

Answer 19

c=15

Answer 20

ok after you have your d value plug it into your orginal equation and solve for c

Answer 21

Got it:)