Question

Sarah went to an electronics store, purchased 3 CDs and 5 DVDs, and spent $137. Michelle went to the same store, bought 2 CDs and 7 DVDs, and spent $161. How much does each CD sell for at the store?

A. $18
B. $13
C. $19
D. $14

Answer 1

a=cd
b=dvd

3a+5b=137
2a+7b=161

2(3a+5b=137)
-3(2a+7b=161)

6a+10b=274
-6a-21b=-483
------------------------
-11b==-209
b=19 each dvd = $19

6a+190=274
6a=84
a=14 each cd = $ 14

Answer 2

D

Answer 3

3x+5y=137
2x+7y=161
where x is

Answer 4

god u r so fast!!

Answer 5

it's D-$14

Answer 6

14

Answer 7

let price of CD=x
price of DVD=y

3x+5y=137
2x+7y=161
----------
2*(3x+5y=137)
-3*(2x+7y=161)
--------------------
6x+10y=274
-6x-21y=-483
------------------------
-11y==-209

y=19
price of DVD = $19

plug value of y in eqn
6x+10y=274

6x+190=274
6x=84
x=14
price of CD = $ 14