SOLUTION: Suppose you bought supplies for a party. Three rolls of streamers and 15 party hats cost $30. Later, you bought 2 rolls of streamers and 4 party hats for $11. How much did each rol

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: Suppose you bought supplies for a party. Three rolls of streamers and 15 party hats cost $30. Later, you bought 2 rolls of streamers and 4 party hats for $11. How much did each rol      Log On


   

Question 249868: Suppose you bought supplies for a party. Three rolls of streamers and 15 party hats cost $30. Later, you bought 2 rolls of streamers and 4 party hats for $11. How much did each roll of streamers cost? How much did each party hat cost?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Suppose you bought supplies for a party.
Three rolls of streamers and 15 party hats cost $30.
Later, you bought 2 rolls of streamers and 4 party hats for $11.
How much did each roll of streamers cost?
How much did each party hat cost?
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Equations:
3s + 15h = 30
2s + 4h = 11
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Multiply thru 1st by 2 ; Multiply thru 2nd by 3.
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6s + 30h = 60
6s + 12h = 33
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Subtract 2nd from 1st:
18h = 27
h = 3/2 = $1.50 (price of each hat)
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Substitute into 2s + 4h = 11 to solve for "s".
2s + 4*(3/2) = 11
2s + 6 = 11
2x = 5
x = $2.50 (price of one streamer)
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Cheers,
Stan H.