SOLUTION: Suppose you have 28 coins that total $2.25. Some coins are dimes and some are nickels. How many of each do you have?

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Question 1018031: Suppose you have 28 coins that total $2.25. Some coins are dimes and some are nickels. How many of each do you have?
Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
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D=dimes; N=nickels
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D+N=28
D=28-N . Use this to substitute for D below.
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$0.05N+$0.10D=$2.25 Substitute for D from above.
$0.05N+$0.10(28-N)=$2.25
$0.05N+$2.80-$0.10N=$2.25
-$0.05N=-$0.55
N=11
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D=28-N=28-11=17
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ANSWER: There are 11 nickels and17 dimes.
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CHECK:
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$0.05N+$0.10D=$2.25
$0.05(11)+$0.10(17)=$2.25
$0.55+$1.70=$2.25
$2.25=$2.25
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