document.write( "Question 857917: I paid my bill using dimes only. If i had paid using only quarters, I would have needed 18 fewer coins. Jow much was my bill? \n" ); document.write( "

Algebra.Com's Answer #516922 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+d+\"$ = number of dimes needed
\n" ); document.write( "Let $\"+q+\"$ = number of quarters if they were used
\n" ); document.write( "------------------
\n" ); document.write( "The bill is: $\"+10d+\"$
\n" ); document.write( " $\"+q+=+d+-+18+\"$
\n" ); document.write( "The bill is also:
\n" ); document.write( " $\"+25q+\"$
\n" ); document.write( "and, by substitution:
\n" ); document.write( " $\"+25%2A%28+d+-+18+%29+\"$
\n" ); document.write( "-------------------
\n" ); document.write( "I can say:
\n" ); document.write( " $\"+10d+=+25%2A%28+d+-+18+%29+\"$
\n" ); document.write( " $\"+10d+=+25d+-+450+\"$
\n" ); document.write( " $\"+15d+=+450+\"$
\n" ); document.write( " $\"+d+=+30+\"$
\n" ); document.write( "and
\n" ); document.write( " $\"+q+=+d+-+18+\"$
\n" ); document.write( " $\"+q+=+30+-+18+\"$
\n" ); document.write( " $\"+q+=+12+\"$
\n" ); document.write( "----------------
\n" ); document.write( "The bill is:
\n" ); document.write( " $\"+10d+=+10%2A30+=+300+\"$
\n" ); document.write( "This is $\"+300+\"$ cents or $3.00
\n" ); document.write( "-----------------------------
\n" ); document.write( "Or, if quarters were used:
\n" ); document.write( " $\"+25q+=+25%2A12+\"$
\n" ); document.write( " $\"+25q+=+300+\"$ or $3.00
\n" ); document.write( "OK\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );