document.write( "Question 1048618: A piggy bank contains 18 coins, all quarters and dimes. Find the number of each types of coins if the value of the coins is $2.40 \n" ); document.write( "

Algebra.Com's Answer #664210 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+q+\"$ = number of quarters
\n" ); document.write( "Let $\"+d+\"$ = number of dimes
\n" ); document.write( "--------------------------------
\n" ); document.write( "(1) $\"+q+%2B+d+=+18+\"$
\n" ); document.write( "(2) $\"+25q+%2B+10d+=+240+\"$ ( in cents )
\n" ); document.write( "----------------------------------
\n" ); document.write( "(2) $\"+5q+%2B+2d+=+48+\"$
\n" ); document.write( "Multiply both sides of (1) by $\"2\"$
\n" ); document.write( "and subtract (1) from (2)
\n" ); document.write( "(2) $\"+5q+%2B+2d+=+48+\"$
\n" ); document.write( "(1) $\"+-2q+-+2d+=+-36+\"$
\n" ); document.write( "----------------------
\n" ); document.write( " $\"+3q+=+12+\"$
\n" ); document.write( " $\"+q+=+4+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+q+%2B+d+=+18+\"$
\n" ); document.write( "(1) $\"+4+%2B+d+=+18+\"$
\n" ); document.write( "(1) $\"+d+=+14+\"$
\n" ); document.write( "--------------------
\n" ); document.write( "There are 4 quarters and 14 dimes
\n" ); document.write( "----------------------------------
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+25q+%2B+10d+=+240+\"$
\n" ); document.write( "(2) $\"+25%2A4+%2B+10%2A14+=+240+\"$
\n" ); document.write( "(2) $\"+100+%2B+140+=+240+\"$
\n" ); document.write( "(2) $\"+240+=+240+\"$
\n" ); document.write( "OK \n" ); document.write( "

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