document.write( "Question 699423: Please help! \r
\n" ); document.write( "\n" ); document.write( "Kelley has a total of $6 in dimes and quarters. If she has a total of 30 coins, how many quarters does she have? And I have to use it in substitution form and elimination form. \n" ); document.write( "

Algebra.Com's Answer #431359 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+d+\"$ = number of dimes she has
\n" ); document.write( "Let $\"+q+\"$ = number of quarters she has
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"+d+%2B+q+=+30+\"$
\n" ); document.write( "(2) $\"+10d+%2B+25q+=+600+\"$ ( in cents )
\n" ); document.write( "----------------------
\n" ); document.write( "Using substitution,
\n" ); document.write( "(1) $\"+q+=+30+-+d+\"$
\n" ); document.write( "(2) $\"+10d+%2B+25%2A%28+30+-+d+%29+=+600+\"$
\n" ); document.write( "(2) $\"+10d+%2B+750+-+25d+=+600+\"$
\n" ); document.write( "(2) $\"+-15d+=+-150+\"$
\n" ); document.write( "(2) $\"+d+=+10+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+d+%2B+q+=+30+\"$
\n" ); document.write( "(1) $\"+10+%2B+q+=+30+\"$
\n" ); document.write( "(1) $\"+q+=+20+\"$
\n" ); document.write( "She has 10 dimes and 20 quarters
\n" ); document.write( "------------------------------
\n" ); document.write( "You can do it by elimination, too
\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) $\"+-10d+-+10q+=+-300+\"$
\n" ); document.write( " $\"+15q+=+300+\"$
\n" ); document.write( " $\"+q+=+20+\"$
\n" ); document.write( " $\"+d+=+10+\"$
\n" ); document.write( "OK\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

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