SOLUTION: marty has 30 quarters, dimes and nickels. the total value marty has in coins is $4.50. she has three times as many nickels as dimes. how many of each coin does marty have?

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Question 358951: marty has 30 quarters, dimes and nickels. the total value marty has in coins is $4.50. she has three times as many nickels as dimes. how many of each coin does marty have?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
1.N%2BD%2BQ=30
2.5N%2B10D%2B25Q=450
3.N=3D
Substituting eq. 3 into eq. 1,
3D%2BD%2BQ=30
4.4D%2BQ=30
Substituting eq. 3 into eq. 2,
5%283D%29%2B10D%2B25Q=450
25D%2B25Q=450
5.D%2BQ=18
Subtract eq. 4 from eq. 5,
4D%2BQ-D-Q=30-18
3D=12
highlight%28D=4%29
Then from eq. 5,
4%2BQ=18
highlight%28Q=14%29
Then from eq. 3,
N=3D
highlight%28N=12%29
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12 nickels, 4 dimes, and 14 quarters.