SOLUTION: tina has 20 coins in dimes and quarters. their total value is $3.20. how many coins of each type does she have?

Question 827008: tina has 20 coins in dimes and quarters. their total value is $3.20. how many coins of each type does she have?
Answer by TimothyLamb(4379) (Show Source): You can put this solution on YOUR website!
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x = dimes
y = quarters
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x + y = 20
10x + 25y = 320
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copy and paste the above linear system in standard form into this matrix-method solver:
https://sooeet.com/math/system-of-linear-equations-solver.php
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solution:
x = dimes = 12
y = quarters = 8
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system matrix
1 1
10 25
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inverse of system matrix
1.6666667 -0.066666667
-0.66666667 0.066666667
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determinant of system matrix = 15
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Solve systems of linear equations up to 6-equations 6-variables:
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