document.write( "Question 554385: mary has 30 coins made up of nickels and dimes. Together they are worth 2.40. How many nickels does mary have? \n" ); document.write( "

Algebra.Com's Answer #361316 by Maths68(1474) $\"\"$ $\"About$

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Let
\n" ); document.write( "Mary has x number of Nickels
\n" ); document.write( "Mary has 30-x number of Dimes\r
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\n" ); document.write( "\n" ); document.write( "Given
\n" ); document.write( "Sum of the coins = 2.40 * 100 (Convert $ into cents)
\n" ); document.write( "Sum of the coins = 240\r
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\n" ); document.write( "\n" ); document.write( "Nickels+Dimes=Sum of the coins
\n" ); document.write( "5*(x)+10*(30-x)=240
\n" ); document.write( "5x+300-10x=240
\n" ); document.write( "-5x=240-300
\n" ); document.write( "-5x=-60
\n" ); document.write( "-5x/-5=-60/-5
\n" ); document.write( "x=12\r
\n" ); document.write( "\n" ); document.write( "Nickels = x = 12
\n" ); document.write( "Dimes = 30-x=30-12=18\r
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\n" ); document.write( "\n" ); document.write( "Check
\n" ); document.write( "=====
\n" ); document.write( "= 12 * 5 + 10*18
\n" ); document.write( "= 60+180
\n" ); document.write( "= 240 cents
\n" ); document.write( "= 240/100 (Convert cents into $)
\n" ); document.write( "= $2.40\r
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