Question 900079: a vending machine has $20.50 in dimes and quarters. If the number of quarters is 5 more than dimes, how many of each type are there? Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! a vending machine has $20.50 in dimes and quarters. If the number of quarters is 5 more than dimes, how many of each type are there?
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Value Equation:: 10d + 25q = 2050 cents
Quantity Equation:: q = d + 5
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Modify:: 2d + 5q = 410
:::::::: q = d + 5
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Substitute for "q" and solve for "d"::
2d + 5(d+5) = 410
2d + 5d + 25 = 410
7d = 385
d = 57 (# of dimes)
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Solve for "q"::
q = d + 5
q = 63 (# of quarters)
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Cheers,
Stan H.
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