document.write( "Question 203989: Jon throws all his nickels and dimes in a jar at home each day. He counted all his coins one day and found that he had collected $42.35. If there were five times as many nickels as dimes how many of each coin does he have? \n" ); document.write( "
Algebra.Com's Answer #153911 by Theo(13342) You can put this solution on YOUR website! let n = number of nickels \n" ); document.write( "let d = number of dimes \n" ); document.write( "since a nickel is worth .05 and a dime is worth .1, then the total money you have is given by the equation: \n" ); document.write( ".05*n + .1*d = 42.35 \n" ); document.write( "----- \n" ); document.write( "since the number of nickels = 6 times the number of dimes, you can replace n with 5d in your equation. \n" ); document.write( "----- \n" ); document.write( "you get: \n" ); document.write( ".05*5d + .1*d = 42.35 \n" ); document.write( "this becomes: \n" ); document.write( "d*(.05*5 + .1) = 42.35 which becomes .35d = 42.35 which becomes d = 121. \n" ); document.write( "----- \n" ); document.write( "the number of dimes is 121. \n" ); document.write( "the number of nickels is 5 * the number of dimes is 121*5 = 605. \n" ); document.write( "121 * .1 = 12.1 \n" ); document.write( ".05 * 605 = 30.25 \n" ); document.write( "30.25 + 12.1 = 42.35 \n" ); document.write( "your answer is good. \n" ); document.write( "----- \n" ); document.write( "the key here is the number of nickels and dimes and the value of each. \n" ); document.write( "n = number of nickels and .05 * n = value of the number of nickels \n" ); document.write( "d = number of dimes and .1 * d = value of the number of dimes \n" ); document.write( ".05*n + .1*d = 42.35 is the value equation you have to work with. \n" ); document.write( "you can substitute 5d for n because the number of nickels = 5 times the number of dimes as stated. \n" ); document.write( "this does not change anything else in the value equation except that n has been replaced with 5d because the number of nickels is equal to the number of dimes. \n" ); document.write( "this allows you to reduce the number of unknowns in your equation from 2 to 1 which allows you to solve for the number of dimes which then allows you to solve for the number of nickels. \n" ); document.write( "----- \n" ); document.write( " |