document.write( "Question 541310: Matt has twice as many quarters as dimes in his coin collection. if dimes and quarters together total $9.00 how many of each kind of coin does he have? \n" ); document.write( "

Algebra.Com's Answer #354146 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"d\"$ = number of quarters
\n" ); document.write( "Let $\"q\"$ = number of quarters
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"+q+=+2d+\"$
\n" ); document.write( "(2) $\"+10d+%2B+25q+=+900+\"$ ( in cents )
\n" ); document.write( "Substitute (1) into (2)
\n" ); document.write( "(2) $\"+10d+%2B+25%2A%282d%29+=+900+\"$
\n" ); document.write( "(2) $\"+10d+%2B+50d+=+900+\"$
\n" ); document.write( "(2) $\"+60d+=+900+\"$
\n" ); document.write( "(2) $\"+d+=+15+\"$
\n" ); document.write( "and, since
\n" ); document.write( "(1) $\"+q+=+2d+\"$
\n" ); document.write( "(1) $\"+q+=+2%2A15+\"$
\n" ); document.write( "(1) $\"+q+=+30+\"$
\n" ); document.write( "He has 15 dimes and 30 quarters
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+10%2A15+%2B+25%2A30+=+900+\"$
\n" ); document.write( "(2) $\"+150+%2B+750+=+900+\"$
\n" ); document.write( "(2) $\"+900+=+900+\"$
\n" ); document.write( "OK \n" ); document.write( "

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