SOLUTION: A box contains $9.00 in nickels, dimes, and quarters. There are 53 coins in all, and the sum of the numbers of nickels and dimes is 3 less than the number of quarters. How many coi
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Question 827119: A box contains $9.00 in nickels, dimes, and quarters. There are 53 coins in all, and the sum of the numbers of nickels and dimes is 3 less than the number of quarters. How many coins of each kind are there?
You can put this solution on YOUR website! ---
x = nickels
y = dimes
z = quarters
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5x + 10y + 25z = 900
x + y + z = 53
x + y = z - 3
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put the system of linear equations into standard form:
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5x + 10y + 25z = 900
x + y + z = 53
x + y - z = -3
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copy and paste the above linear system in standard form into this matrix-method solver:
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solution:
x = nickels = 10
y = dimes = 15
z = quarters = 28
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system matrix
5 10 25
1 1 1
1 1 -1
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inverse of system matrix
-0.2 3.5 -1.5
0.2 -3 2
0 0.5 -0.5
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determinant of system matrix = 10
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