document.write( "Question 271947: I am studying matrices, but have a hard time translating word problems. How would you set this up in a matrix?\r
\n" ); document.write( "\n" ); document.write( "On counting the money in her piggy bank, Sally found that she had 122 coins, all nickels, dimes, and quarters. If the total value of the coins was $15, and the total value of the quarters was 4 times the total value of the nickels, how many of each kind of coin did Sally have?\r
\n" ); document.write( "\n" ); document.write( "Thanks in advance!
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Algebra.Com's Answer #199013 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
First write an equation for each statement
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\n" ); document.write( "On counting the money in her piggy bank, Sally found that she had 122 coins, all nickels, dimes, and quarters.
\n" ); document.write( "n + d + q = 122
\n" ); document.write( ":
\n" ); document.write( "If the total value of the coins was $15,
\n" ); document.write( ".05n + .10d + .25q = 15.00
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\n" ); document.write( "and the total value of the quarters was 4 times the total value of the nickels,
\n" ); document.write( ".25q = 4(.05n)
\n" ); document.write( ".25q = .20n
\n" ); document.write( "-.20n + .25q = 0
\n" ); document.write( "We want it in this form for the matrix
\n" ); document.write( "-.20n + 0d + .25q = 0
\n" ); document.write( ":
\n" ); document.write( "Here is the matrix from these three equations
\n" ); document.write( " 1 + 1 + 1 = 122
\n" ); document.write( ".05 + .1 + .25 = 15
\n" ); document.write( "-.2 + 0 + .25 = 0
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\n" ); document.write( "Using the matrix feature in my Ti83, I got
\n" ); document.write( "n = 40
\n" ); document.write( "d = 50
\n" ); document.write( "q = 32\r
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