document.write( "Question 281982: Sharing cost. The members of a flying club plan to share equally the cost of a $200,000 airplane. The members want to find five more people to join the club so that the cost per person will decrease by $2000. How many members are currently in the club? \n" ); document.write( "
Algebra.Com's Answer #204809 by josmiceli(19441)\"\" \"About 
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Let \"x\" = current number of members in club
\n" ); document.write( "Let \"C\" = current cost per person
\n" ); document.write( "given:
\n" ); document.write( "\"C+=+200000%2Fx\"
\n" ); document.write( "\"C+-+2000+=+200000%2F%28x+%2B+5%29\"
\n" ); document.write( "-------------------------
\n" ); document.write( "By substitution:
\n" ); document.write( "\"200000%2Fx+-+2000+=+200000%2F%28x+%2B+5%29\"
\n" ); document.write( "Multiply both sides by \"x%2A%28x%2B5%29\"
\n" ); document.write( "\"200000%2A%28x+%2B+5%29+-+2000%2Ax%2A%28x%2B5%29+=++200000x\"
\n" ); document.write( "\"200000x+%2B+1000000+-+2000x%5E2+-+10000x+=+200000x\"
\n" ); document.write( "divide both sides by \"1000\"
\n" ); document.write( "\"200x+%2B+1000+-+2x%5E2+-+10x+=+200x\"
\n" ); document.write( "\"2x%5E2+%2B+10x+-+1000+=+0\"
\n" ); document.write( "\"x%5E2+%2B+5x+-+500+-+0\"
\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"
\n" ); document.write( "\"a+=+1\"
\n" ); document.write( "\"b+=+5\"
\n" ); document.write( "\"c+=+-500\"
\n" ); document.write( "\"x+=+%28-5+%2B-+sqrt%28+5%5E2-4%2A1%2A%28-500%29+%29%29%2F%282%2A1%29+\"
\n" ); document.write( "\"x+=+%28-5+%2B-+sqrt%28+25+%2B+2000+%29%29%2F2+\"
\n" ); document.write( "\"x+=+%28-5+%2B-+sqrt%282025%29%29%2F2\"
\n" ); document.write( "\"x+=+%28-5+%2B+45%29%2F2\"
\n" ); document.write( "\"x+=+20\" (the negative root is invalid)
\n" ); document.write( "There are currently 20 members
\n" ); document.write( "check:
\n" ); document.write( "\"C+=+200000%2Fx\"
\n" ); document.write( "\"C+=+200000%2F20\"
\n" ); document.write( "\"C+=+10000\"
\n" ); document.write( "and
\n" ); document.write( "\"C+-+2000+=+200000%2F%28x+%2B+5%29\"
\n" ); document.write( "\"10000+-+2000+=+200000%2F%2820+%2B+5%29\"
\n" ); document.write( "\"8000+=+200000%2F25\"
\n" ); document.write( "\"8000+=+8000\"
\n" ); document.write( "OK
\n" ); document.write( "
\n" );