document.write( "Question 990564: David Bowers collects us gold coins. He has a collection of 47 coins. some are $10 coins, and the rest are $20 coins. If the face value of the coins is $690, how many of each denomination does he have? \n" ); document.write( "
Algebra.Com's Answer #610566 by macston(5194)\"\" \"About 
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\n" ); document.write( "x=number of $10 coins; y=number of $20 coins
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\n" ); document.write( "x+y=47
\n" ); document.write( "x=47-y
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\n" ); document.write( "$10x+$20y=$690
\n" ); document.write( "$10(47-y)+$20y=$690
\n" ); document.write( "$470-$10y+$20y=$690
\n" ); document.write( "$10y=$220
\n" ); document.write( "y=22
\n" ); document.write( "ANSWER 1: He has twenty two 420 coins.
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\n" ); document.write( "x=47-y=47-22=25
\n" ); document.write( "ANSWER 2: He has twenty five $10 coins.
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\n" ); document.write( "CHECK:\r
\n" ); document.write( "\n" ); document.write( "$10x+$20y=$690
\n" ); document.write( "$10(25)+$20(22)=$690
\n" ); document.write( "$250+$440=$690
\n" ); document.write( "$690=$690\r
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