document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=106506>Question 106506</A>: <I><SPAN STYLE=\"word-break: break-all;\"> word problem for quadratic equation\r<BR>\n" );
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document.write( "Brendan buys a block of shares of Laser Technology for $1875. When the share price increases by $4 per share, he sells all but 15 of them for $1740. How many shares did he buy?\r<BR>\n" );
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document.write( "can anyone set-up the equation for this?? thanks for your help...<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #77515 by </B><A HREF=/tutors/aboutme.mpl?userid=edjones><B>edjones(8007)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=edjones><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=edjones><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=77515\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let x=number of shares he bought. p=share price he paid<BR>\n" );
document.write( "A) xp=1875<BR>\n" );
document.write( "B) (p+4)(x-15)=1740<BR>\n" );
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document.write( "A) x=1875/p<BR>\n" );
document.write( "B) px+4x-15p-60=1740 Expand<BR>\n" );
document.write( "p*1875/p + 4*1875/p - 15p-60=1740 substitute 1875/p for x<BR>\n" );
document.write( "1875+7500/p-15p-60=1740 cancel<BR>\n" );
document.write( "1875p+7500-15p^2-60p=1740p multiply both sides by p to eliminate fraction.<BR>\n" );
document.write( "-15p^2+75p+7500=0<BR>\n" );
document.write( "15p^2-75p-7500=0<BR>\n" );
document.write( "15(p^2-5p-500)=0<BR>\n" );
document.write( "15(p-25)(p+20)=0<BR>\n" );
document.write( "p= -20 is extraneous to this problem.<BR>\n" );
document.write( "p=$25<BR>\n" );
document.write( "x=1875/25= 75 shares Answer<BR>\n" );
document.write( "Check:<BR>\n" );
document.write( "60*29=$1740.<BR>\n" );
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document.write( "Ed\r<BR>\n" );
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