SOLUTION: Paula belongs to a music club. When she buys 7 compact disks and 2 cassettes, she spends $119. If she buys 5 compact disks and 4 cassettes, she spends $103. What is the cost of

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: Paula belongs to a music club. When she buys 7 compact disks and 2 cassettes, she spends $119. If she buys 5 compact disks and 4 cassettes, she spends $103. What is the cost of       Log On

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Question 1028176: Paula belongs to a music club. When she buys 7 compact disks and 2 cassettes, she spends $119. If she buys 5 compact disks and 4 cassettes, she spends $103. What is the cost of each item?
Answer by Cromlix(4381) About Me  (Show Source):
You can put this solution on YOUR website!
HI there,
Make the compact discs = x
Make the cassettes = y
7x + 2y = 119........(1)
5x + 4y = 103........(2)
Multiply Eq(1) by 2
14x + 4y = 238.......(1)
5x + 4y = 103.......(2)
Subtract (2) from (1)
9x = 135
x = 15
Substitute x = 15 in Eq(2)
5x + 4y = 103........(2)
5(15) + 4y = 103
75 + 4y = 103
4y = 103 - 75
4y = 28
y = 7
Compact discs cost $15
Cassettes cost $7
Hope this helps :-)