SOLUTION: I am trying to write and solve a system of equation. THe question is 3 large popcorns and 2 small drinks cost $21.00 and another customer bought 2 large popcorns and 4 small drink

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: I am trying to write and solve a system of equation. THe question is 3 large popcorns and 2 small drinks cost $21.00 and another customer bought 2 large popcorns and 4 small drink      Log On


   

Question 588103: I am trying to write and solve a system of equation. THe question is 3 large popcorns and 2 small drinks cost $21.00 and another customer bought 2 large popcorns and 4 small drinks for $22.00. Find the cost of a large popcorn and the cost of a small drink.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
THe question is 3 large popcorns and 2 small drinks cost $21.00 and another customer bought 2 large popcorns and 4 small drinks for $22.00. Find the cost of a large popcorn and the cost of a small drink.
Equations:
3p + 2d = 21
2p + 4d = 22
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Multiply thru the 1st equation by 2 to get:
6p + 4d = 42
2p + 4d = 22
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Subtract and solve for "p":
4p = 20
p = $5.00 (cost of one large popcorn)
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Solve for "d":
3p + 2d = 21
3*5 + 2d = 21
15 + 2d = 21
2d = 6
d = $3.00 (cost on one drink)
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Cheers,
Stan H.
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