document.write( "Question 179554: Joe has a collection of nickels and dimes that is worth $6.05. If the number of dimes was doubled and the number of nickels was decreased by 10, the value of the coins would be $9.85. How many dimes does he have? \n" ); document.write( "
Algebra.Com's Answer #134493 by nerdybill(7384)\"\" \"About 
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Joe has a collection of nickels and dimes that is worth $6.05. If the number of dimes was doubled and the number of nickels was decreased by 10, the value of the coins would be $9.85. How many dimes does he have?
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\n" ); document.write( "Let d = number of dimes
\n" ); document.write( "and n = number of nickels
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\n" ); document.write( "From:\"Joe has a collection of nickels and dimes that is worth $6.05.\"
\n" ); document.write( ".10d + .05n = 6.05 (equation 1)
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\n" ); document.write( "From:\"If the number of dimes was doubled and the number of nickels was decreased by 10, the value of the coins would be $9.85\"
\n" ); document.write( ".10(2d) + .05(n-10) = 9.85
\n" ); document.write( ".20d + .05n-.5 = 9.85
\n" ); document.write( ".20d + .05n = 10.35 (equation 2)
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\n" ); document.write( "Solve equation 1 for n:
\n" ); document.write( ".10d + .05n = 6.05
\n" ); document.write( ".05n = 6.05 - .10d
\n" ); document.write( "n = 121 - 2d
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\n" ); document.write( "Plug the above into equation 2 and solve for d:
\n" ); document.write( ".20d + .05n = 10.35
\n" ); document.write( ".20d + .05(121 - 2d) = 10.35
\n" ); document.write( ".20d + 6.05 - .1d = 10.35
\n" ); document.write( ".10d + 6.05 = 10.35
\n" ); document.write( ".10d = 4.3
\n" ); document.write( "d = 43 dimes
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