Question 833359
Trisha has a bag with 32 dimes and nickels worth $2.80. How many of each coin does she have?
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Equations:
Quantity: n + d = 32 coins
Value::  5n +10d= 280 cents
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Modify for elimination:
5n + 5d = 5*32
5n + 10d = 280
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Subtract and solve for "d":
5d = 120
d = 24 (# of dimes)
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n + d = 32
n = 32-24 = 8 (# of nickels)

Cheers,
Stan H.
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