document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=67792>Question 67792</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A farmer normally plows a rectangular field 80ft by 120 ft.  This year the farmer wants to expand the area of the field by 20%, by extending the width and length of the plowed area an equal amount. How much wider and longer should the farmer plow the field to obtain a 20% increase in area? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #48215 by </B><A HREF=/tutors/aboutme.mpl?userid=checkley71><B>checkley71(8403)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=checkley71><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=48215\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> CURRENT AREA=80*120=9600<BR>\n" );
document.write( "TO INCREASE THIS AREA BY 20% IT MUST BE 9600*1.2=11520<BR>\n" );
document.write( "THUS (80+X)(120+X)=11520<BR>\n" );
document.write( "9600+120X+80X+X^2=11520<BR>\n" );
document.write( "X^2+200X+9600-11520=0<BR>\n" );
document.write( "X^2+200X-1920=0<BR>\n" );
document.write( "USING THE QUADRATIC EQUATION WE GET<BR>\n" );
document.write( "X=(-B+-SQRT[B^2-4AC])/2A<BR>\n" );
document.write( "X=(-200+-SQRT[200*200-4*1*-1920])/2*1<BR>\n" );
document.write( "X=(-200+-SQRT[40000+7680])/2<BR>\n" );
document.write( "X=(-200+-SQRT47680])/2<BR>\n" );
document.write( "X=(-200+-218.3578)/2<BR>\n" );
document.write( "X=-200+218.3578)/2<BR>\n" );
document.write( "X=18.3578/2<BR>\n" );
document.write( "X=9.17875 ANSWER. </SPAN>\n" );
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