document.write( "Question 683734: Mark has 42 coins consisting of dimes and quarters. the total value of his coins is $6. How many of each type of coin does he have? show all your work and explain what method you used to solve the problem.
\n" ); document.write( "In advance I will like to say Thank you. \n" ); document.write( "

Algebra.Com's Answer #423685 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+d+\"$ = number of dimes he has
\n" ); document.write( "Let $\"+q+\"$ = number of quarters he has
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"+d+%2B+q+=+42+\"$
\n" ); document.write( "(2) $\"+10d+%2B+25q+=+600+\"$ ( in cents )
\n" ); document.write( "----------------------
\n" ); document.write( "Multiply both sides of (1) by $\"+10+\"$
\n" ); document.write( "and subtract (1) from (2)
\n" ); document.write( "(2) $\"+10d+%2B+25q+=+600+\"$
\n" ); document.write( "(1) $\"+-10d+-+10q+=+-420+\"$
\n" ); document.write( " $\"+15q+=+180+\"$
\n" ); document.write( " $\"+q+=+12+\"$
\n" ); document.write( "and, since
\n" ); document.write( "(1) $\"+d+%2B+q+=+42+\"$
\n" ); document.write( "(1) $\"+d+%2B+12+=+42+\"$
\n" ); document.write( "(1) $\"+d+=+30+\"$
\n" ); document.write( "he has 30 dimes and 12 quarters
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+10d+%2B+25q+=+600+\"$
\n" ); document.write( "(2) $\"+10%2A30+%2B+25%2A12+=+600+\"$
\n" ); document.write( "(2) $\"+300+%2B+300+=+600+\"$
\n" ); document.write( "(2) $\"+600+=+600+\"$
\n" ); document.write( "OK \n" ); document.write( "

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