document.write( "Question 515197: a person has 50 coins in dimes and quarters with a combined value of $7.70. Determine the number of coins of each type \n" ); document.write( "

Algebra.Com's Answer #343805 by oberobic(2304) $\"\"$ $\"About$

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d = number of dimes
\n" ); document.write( "10d = value of dimes in cents
\n" ); document.write( "q = number of quarters
\n" ); document.write( "25q = value of quarters in cents
\n" ); document.write( ".
\n" ); document.write( "10d + 25q = 770 cents
\n" ); document.write( ".
\n" ); document.write( "d + q = 50
\n" ); document.write( "so
\n" ); document.write( "d = 50-q
\n" ); document.write( ".
\n" ); document.write( "substitute.
\n" ); document.write( ".
\n" ); document.write( "10(50-q) + 25q = 770
\n" ); document.write( "500 - 10q +25q = 770
\n" ); document.write( "15q = 270
\n" ); document.write( "q = 18
\n" ); document.write( ".
\n" ); document.write( "d = 50-q
\n" ); document.write( "d = 32
\n" ); document.write( ".
\n" ); document.write( "Check the values to make sure they're right.
\n" ); document.write( ".
\n" ); document.write( "25*18 = 450
\n" ); document.write( "10*32 = 320
\n" ); document.write( "Total = 770
\n" ); document.write( ".
\n" ); document.write( "Answer: The person has 18 quarters and 32 dimes.
\n" ); document.write( ".
\n" ); document.write( "Done. \n" ); document.write( "

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