SOLUTION: Some number of dimes plus Nickels equal $7.20 . the number of dimes is three less than twice a number of Nickels how many dimes and nickels are there

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Question 1000014: Some number of dimes plus Nickels equal $7.20 . the number of dimes is three less than twice a number of Nickels how many dimes and nickels are there
Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
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N=number of nickels; D=number of dimes=2N-3
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$0.05N+$0.10D=$7.20 . This converts number of coins to money value.
$0.05N+$0.10(2N-3)=$7.20 . This substitutes for D.
$0.05N+$0.20N-$0.30=$7.20
$0.25N=$7.50
N=30
ANSWER 1: There are 30 nickels.
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D=2N-3
D=2(30)-3
D=60-3=57
ANSWER 2: There are 57 dimes.
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CHECK:
$0.05N+$0.10D=$7.20
$0.05(30)+$0.10(57)=$7.20
$1.50+$5.70=$7.20
$7.20=$7.20
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