document.write( "Question 141777: Sam emptied his collection of nickels and dimes on his bed. If his 46 coins were worth $3.10, how many coins of each type did he have? \n" ); document.write( "
Algebra.Com's Answer #103274 by ptaylor(2198) You can put this solution on YOUR website! Let x=number of nickels \n" ); document.write( "And let y=number of dimes\r \n" ); document.write( "\n" ); document.write( "Now we are told:\r \n" ); document.write( "\n" ); document.write( "x+y=46-------------------------------------------eq1\r \n" ); document.write( "\n" ); document.write( "and($ understood) \n" ); document.write( "0.05x+0.25y=3.10-------------------------------------eq2\r \n" ); document.write( "\n" ); document.write( "Multiply eq1 by 0.05\r \n" ); document.write( "\n" ); document.write( "0.05x+0.05y=2.3------------------------eq1a\r \n" ); document.write( "\n" ); document.write( "Subtract eq1a from eq2\r \n" ); document.write( "\n" ); document.write( "0.20y=0.80 divide both sides by 0.20 \n" ); document.write( "y=4--------------------------------------number of quarters\r \n" ); document.write( "\n" ); document.write( "Substitute y=4 into eq1 \n" ); document.write( "x+4=46 subtract 4 from each side\r \n" ); document.write( "\n" ); document.write( "x+4-4=46-4 collect like terms\r \n" ); document.write( "\n" ); document.write( "x=42-----------------------------number of nickels\r \n" ); document.write( "\n" ); document.write( "CK \n" ); document.write( "42+4=46 \n" ); document.write( "46=46 \n" ); document.write( "and \n" ); document.write( "4*0.25+42*0.05=3.10 \n" ); document.write( "1.00+2.10=3.10 \n" ); document.write( "3.10=3.10\r \n" ); document.write( "\n" ); document.write( "Another way to solve this problem using 1 unknown:\r \n" ); document.write( "\n" ); document.write( "Let x=number of nickels \n" ); document.write( "Then 46-x=number of quarters \n" ); document.write( "0.05x+0.25(46-x)=3.10 get rid of parens \n" ); document.write( "0.05x+11.50-0.25x=3.10 subtract 11.50 from each side\r \n" ); document.write( "\n" ); document.write( "0.05x+11.50-11.50-0.25x=3.10-11.50 collect like terms\r \n" ); document.write( "\n" ); document.write( "-0.20x=-8.40 divide both sides by -0.20 \n" ); document.write( "x=42--------------------------------------------number of nickels\r \n" ); document.write( "\n" ); document.write( "46-42=4--------------------------------------number of quarters\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Hope this helps----ptaylor \n" ); document.write( " |