Question 828383: A parking meter contains $25.50 in dollar coins, quarters, and dimes. There twice as many quarters as dollar coins and as many quarters as there were dimes. Find the number of dollar coins, quarters, and dimes.
Answer by TimothyLamb(4379)   (Show Source):
You can put this solution on YOUR website! ---
x = dimes
y = quarters
z = dollars
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10x + 25y + 100z = 2550
y = 2z
y = x
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put the system of linear equations into standard form:
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10x + 25y + 100z = 2550
y - 2z = 0
x - y = 0
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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 = dimes = 30
y = quarters = 30
z = dollars = 15
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system matrix
10 25 100
0 1 -2
1 -1 0
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inverse of system matrix
0.011764706 0.58823529 0.88235294
0.011764706 0.58823529 -0.11764706
0.0058823529 -0.20588235 -0.058823529
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determinant of system matrix = -170
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