document.write( "Question 116162This question is from textbook
\n" ); document.write( ": Joe has a collection of nickels and dimes that is worth $6.00. If the number of dimes were doubled and the number of nickels were increased by 6, the value of the coins would be $9.90. How many dimes does he have? \n" ); document.write( "
Algebra.Com's Answer #84479 by ankor@dixie-net.com(22740)\"\" \"About 
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Joe has a collection of nickels and dimes that is worth $6.00. If the number of dimes were doubled and the number of nickels were increased by 6, the value of the coins would be $9.90. How many dimes does he have?
\n" ); document.write( ":
\n" ); document.write( "Using the 1st statement we can write an equation:
\n" ); document.write( ".05n + .10d = 6.00
\n" ); document.write( "Rearrange so we can use for substitution
\n" ); document.write( ".05n = 6 - .10d
\n" ); document.write( ":
\n" ); document.write( "Multiply equation by 20 to make the coefficient of n = 1:
\n" ); document.write( "1n = (120 - 2d)
\n" ); document.write( ":
\n" ); document.write( "Using the 2nd statement, write another equation:
\n" ); document.write( "\"If the number of dimes were doubled and the number of nickels were increased by 6, the value of the coins would be $9.90.\"
\n" ); document.write( ":
\n" ); document.write( ".05(n+6) + 2(.10d) = 9.90
\n" ); document.write( ".05n + .3 + .20d = 9.90
\n" ); document.write( ".05n + .2d = 9.9 - .3
\n" ); document.write( ".05n + .2d = 9.6
\n" ); document.write( ":
\n" ); document.write( " How many dimes does he have?
\n" ); document.write( "Substitute (120-2d) for n in the above equation:
\n" ); document.write( ".05(120-2d) + .2d = 9.6
\n" ); document.write( " 6 - .10d + .2d = 9.6
\n" ); document.write( "-.1d + .2d = 9.6 - 6
\n" ); document.write( "+.1d = 3.6
\n" ); document.write( "d = 3.6/.1
\n" ); document.write( "d = 36 dimes in the collection
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "To confirm our solution we need to find out how many nickels:
\n" ); document.write( "n = 120 - 2(36)
\n" ); document.write( "n = 120 - 72
\n" ); document.write( "n = 48 dimes
\n" ); document.write( ":
\n" ); document.write( "Check solution using the 1st statement:
\n" ); document.write( "\"Joe has a collection of nickels and dimes that is worth $6.00.\"
\n" ); document.write( ".05(48) + .10(36) =
\n" ); document.write( "2.40 + 3.60 = $6
\n" ); document.write( ":
\n" ); document.write( "You can check the solutions using the statement:
\n" ); document.write( "\"If the number of dimes were doubled and the number of nickels were increased by 6, the value of the coins would be $9.90.\" \n" ); document.write( "
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