document.write( "Question 113438: A stamp collection consists of 5,13, and 18 cent stamps. The number of 13 cent stamps is one less then twice the number of 5 cent stamps. The number of the 18 cent stamps is five more then the number of 13 cent stamps. The total value of all the stamps is $2.60. Find the number of 13 cent stamps in the collections \n" ); document.write( "
Algebra.Com's Answer #82523 by josmiceli(19441)\"\" \"About 
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F = number of 5c stamps
\n" ); document.write( "T = number of 13c stamps
\n" ); document.write( "E = number of 18c stamps
\n" ); document.write( "\"T+=+2F+-+1\"
\n" ); document.write( "\"E+=+T+%2B+5\"
\n" ); document.write( "\"5F+%2B+13T+%2B+18E+=+260\"
\n" ); document.write( "\"5F+%2B+13%282F+-+1%29+%2B+18E+=+260\"
\n" ); document.write( "\"5F+%2B+13%282F+-+1%29+%2B+18%28T+%2B+5%29+=+260\"
\n" ); document.write( "\"5F+%2B+13%282F+-+1%29+%2B+18%282F+-+1+%2B+5%29+=+260\"
\n" ); document.write( "\"5F+%2B+26F+-+13+%2B+36F+%2B+72+=+260\"
\n" ); document.write( "\"67F+%2B+59+=+260\"
\n" ); document.write( "\"67F+=+260+-+59\"
\n" ); document.write( "\"67F+=+201\"
\n" ); document.write( "\"F+=+3\"
\n" ); document.write( "\"T+=+2F+-+1\"
\n" ); document.write( "\"T+=+6+-+1\"
\n" ); document.write( "\"T+=+5\"
\n" ); document.write( "There are 5 thirteen cent stamps in the collection
\n" ); document.write( "check:
\n" ); document.write( "\"E+=+T+%2B+5\"
\n" ); document.write( "\"E+=+10\"
\n" ); document.write( "\"5F+%2B+13T+%2B+18E+=+260\"
\n" ); document.write( "\"5%2A3+%2B+13%2A5+%2B+18%2A10+=+260\"
\n" ); document.write( "\"15+%2B+65+%2B+180+=+260\"
\n" ); document.write( "\"260+=+260\"
\n" ); document.write( "OK
\n" ); document.write( "
\n" );