document.write( "Question 105059: A change machine contains nickels, dimes, and quarters. There are 75 coins in the machine, and the value of the coins is $7.25. There are 5 times as many nickels as dimes. Find the number of coins of each type in the machine. \n" ); document.write( "
Algebra.Com's Answer #76513 by ankor@dixie-net.com(22740)\"\" \"About 
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:
\n" ); document.write( "A change machine contains nickels, dimes, and quarters.
\n" ); document.write( ":
\n" ); document.write( "Just write an equation for each statement:
\n" ); document.write( ":
\n" ); document.write( "\"There are 75 coins in the machine,\"
\n" ); document.write( "n + d + q = 75
\n" ); document.write( ":
\n" ); document.write( "\"the value of the coins is $7.25.\"
\n" ); document.write( ".05n + .10n + .25q = 7.25
\n" ); document.write( ":
\n" ); document.write( "\" There are 5 times as many nickels as dimes.\"
\n" ); document.write( "n = 5d
\n" ); document.write( ":
\n" ); document.write( "Find the number of coins of each type in the machine.
\n" ); document.write( ":
\n" ); document.write( "Substitute 5d for n in the 1st equation:
\n" ); document.write( "5d + d + q = 75
\n" ); document.write( "6d + q = 75
\n" ); document.write( "q = (75-6d); use this for substitution later
\n" ); document.write( ":
\n" ); document.write( "Substitute 5d for n in the 2nd equation:
\n" ); document.write( ".05(5d) + .10d + .25q = 7.25
\n" ); document.write( ".25d + .10d + .25q = 7.25
\n" ); document.write( ".35d + .25q = 7.25
\n" ); document.write( ":
\n" ); document.write( "In the above equation substitute (75-6d) for q:
\n" ); document.write( ".35d + .25(75-6d) = 7.25
\n" ); document.write( ".35d + 18.75 - 1.5d = 7.25
\n" ); document.write( ".35d - 1.5d = 7.25 - 18.75
\n" ); document.write( "-1.15d = -11.5
\n" ); document.write( "d = -11.5/-1.15
\n" ); document.write( "d = +10 dimes
\n" ); document.write( ":
\n" ); document.write( "Find the nickels from n = 5d
\n" ); document.write( "n = 5(10)
\n" ); document.write( "n = 50 nickels
\n" ); document.write( ":
\n" ); document.write( "Find q using the 1st equation:
\n" ); document.write( "50 + 10 + q = 75
\n" ); document.write( "60 + q = 75
\n" ); document.write( "q = 75 - 60
\n" ); document.write( "q = 15 quarters
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check our solutions on the 2nd equation:.
\n" ); document.write( ".05(50) + .10(10) + .25(15) =
\n" ); document.write( "2.50 + 1.00 + 3.75 = 7.25; confirms our solutions
\n" ); document.write( ":
\n" ); document.write( "Did this makes sense to you? A lot of steps but each one is logical and simple.
\n" ); document.write( "Any questions?
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