document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=168056>Question 168056</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0395977258/algebrahomeworkh>Algebra and Trigonometry</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> The members of a computer club were to be assessed equally to raise $400 for the purchase of software. When four more persons joined the club, the per-member assessment was reduced by $5.00. What was the new size of the club membership? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #123889 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=123889\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The members of a computer club were to be assessed equally to raise $400 for the<BR>\n" );
document.write( " purchase of software. When four more persons joined the club, the per-member<BR>\n" );
document.write( " assessment was reduced by $5.00. What was the new size of the club membership?<BR>\n" );
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document.write( "Let x = new size club membership<BR>\n" );
document.write( "then<BR>\n" );
document.write( "(x-4) = original club membership<BR>\n" );
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document.write( "Original cost per member = New cost per member + $5<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=400%2F%28%28x-4%29%29 ALIGN=MIDDLE  ALT=\"400%2F%28%28x-4%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=400%2Fx ALIGN=MIDDLE  ALT=\"400%2Fx\"   DISABLED_style= \"max-width:90%; height:auto;\" > + 5<BR>\n" );
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document.write( "Multiply equation by x(x-4) to get rid of the denominators, results:<BR>\n" );
document.write( "400x = 400(x-4) + 5x(x-4)<BR>\n" );
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document.write( "400x = 400x - 1600 + 5x^2 - 20x<BR>\n" );
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document.write( "0 = 400x - 400x - 1600 + 5x^2 - 20x <BR>\n" );
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document.write( "A quadratic equation:<BR>\n" );
document.write( "5x^2 - 20x - 1600 = 0<BR>\n" );
document.write( "Simplify, divide equation by 5:<BR>\n" );
document.write( "x^2 - 4x - 320 = 0<BR>\n" );
document.write( "Factor to:<BR>\n" );
document.write( "(x - 20)(x + 16) = 0<BR>\n" );
document.write( "Positive solution is what we want here:<BR>\n" );
document.write( "x = 20 new members<BR>\n" );
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document.write( "Check solution by finding the cost per person<BR>\n" );
document.write( "400/16 = $25<BR>\n" );
document.write( "400/20 = $20<BR>\n" );
document.write( "------------<BR>\n" );
document.write( "differ = $5\r<BR>\n" );
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document.write( " </SPAN>\n" );
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