document.write( "Question 366049: Joe has a collection of nickels and dimes that is worth $9.60. If the number of dimes was tripled and the number of nickels was decreased by 31, the value of the coins would be $6.70. How many nickels and dimes does he have? \n" ); document.write( "
Algebra.Com's Answer #260854 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! Response to student comment, I can solve it algebraically, but the solution \n" ); document.write( "will not make sense as you will see here \n" ); document.write( ": \n" ); document.write( "Let n = no. of nickels \n" ); document.write( "Let d = no. of dimes \n" ); document.write( ": \n" ); document.write( "Write an equation for each statement: \n" ); document.write( ": \n" ); document.write( "\"Joe has a collection of nickels and dimes that is worth $9.60.\" \n" ); document.write( ".05n + .10d = 9.60 \n" ); document.write( ": \n" ); document.write( "If the number of dimes was tripled and the number of nickels was decreased by 31, the value of the coins would be $6.70.\" \n" ); document.write( ".05(n-31) + .10(3d) = 6.70 \n" ); document.write( ".05n - 1.55 + .30d = 6.70 \n" ); document.write( ".05n + .30d = 6.70 + 1.55 \n" ); document.write( ".05n + .30d = 8.25 \n" ); document.write( ": \n" ); document.write( "Use elimination here, subtract the 1st equation from the above equation \n" ); document.write( ".05n + .30d = 8.25 \n" ); document.write( ".05n + .10d = 9.60 \n" ); document.write( "----------------------subtraction eliminates n, find d \n" ); document.write( "0 + .20d = -1.35 \n" ); document.write( "d = \n" ); document.write( "d = -6.75 dimes, which is, of course, ridiculous \n" ); document.write( ": \n" ); document.write( "Let's just think about it. \n" ); document.write( "Triple the no. of dimes and get $2.90 less even if you subtract 31 nickels \n" ); document.write( " (which is $1.55) does not seem right does it? \n" ); document.write( ": \n" ); document.write( "I did a quick calc using the statement: \n" ); document.write( "\"If the number of nickels was tripled and the number of dime was decreased \n" ); document.write( " by 31, the value of the coins would be $6.70.\" \n" ); document.write( "and got a valid solution of 2 nickels and 95 dimes \n" ); document.write( ": \n" ); document.write( "What do you think about it? Are there others in your class doing this. Call \n" ); document.write( "them up and see what they think. \r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |