document.write( "Question 263592: Mary emptied the change in the bottom of her purse. She found all quarters and dimes, worth a total of $10.25. The number of quarters was 7 less than twice the number of dimes. How many of each type of coin did she have? \n" ); document.write( "

Algebra.Com's Answer #194242 by drk(1908) $\"\"$ $\"About$

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This is a money equation. We need two equations.
\n" ); document.write( "(i) $\"10d+%2B+25q+=+1025\"$
\n" ); document.write( "(ii) $\"q+=+2d+-+7\"$
\n" ); document.write( "step 1 - substitute (ii) into (i) to get
\n" ); document.write( "(iii) $\"10d+%2B+25%282d-7%29+=+1025\"$
\n" ); document.write( "step 2 - distribute to get
\n" ); document.write( "(iv) $\"10d+%2B+50d+-+175+=+1025\"$
\n" ); document.write( "step 3 - combine like terms to get
\n" ); document.write( "(v) $\"60d+-175+=+1025\"$
\n" ); document.write( "add 175 to get
\n" ); document.write( " (vi) $\"60d+=+1200\"$
\n" ); document.write( "d = 20
\n" ); document.write( "and from (ii)
\n" ); document.write( "q = 33
\n" ); document.write( " \n" ); document.write( "

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