document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=398013>Question 398013</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A rectangular plot of ground having dimensions 21 ft by 24 ft is surrounded by a walk of uniform width. If the area of the walk is 424 ft2, what is its width? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #282043 by </B><A HREF=/tutors/aboutme.mpl?userid=mananth><B>mananth(16946)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=mananth><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=mananth><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=282043\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A rectangular plot of ground having dimensions 21 ft by 24 ft is surrounded by a walk of uniform width. If the area of the walk is 424 ft2, what is its width?<BR>\n" );
document.write( "..\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "area of ground = 21*24=504 ft^2<BR>\n" );
document.write( "...<BR>\n" );
document.write( "area of walk = 424 ft^2<BR>\n" );
document.write( "..<BR>\n" );
document.write( "let width of walk be x<BR>\n" );
document.write( "..<BR>\n" );
document.write( "width of total area = 21+2x<BR>\n" );
document.write( "length of total area = 24+2x<BR>\n" );
document.write( "..<BR>\n" );
document.write( "Area of total area = (21+2x)(24+2x)<BR>\n" );
document.write( "Total Area = 504+90x+4x^2<BR>\n" );
document.write( "..<BR>\n" );
document.write( "4x^2+90x+504-504 = 424<BR>\n" );
document.write( "4x^2+90x-424=0\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Find the roots of the equation by quadratic formula<BR>\n" );
document.write( "a= 4  , b =90   , c = -424    .\r<BR>\n" );
document.write( "\n" );
document.write( "b^2-4ac=14884<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29 ALIGN=MIDDLE  ALT=\"x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x1=%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29 ALIGN=MIDDLE  ALT=\"x1=%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x1=%28-90%2Bsqrt%2814884%29%29%2F8%29%29 ALIGN=MIDDLE  ALT=\"x1=%28-90%2Bsqrt%2814884%29%29%2F8%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "x1= 4<BR>\n" );
document.write( "x2= negative so ignore\r<BR>\n" );
document.write( "\n" );
document.write( "walk width = 4 feet<BR>\n" );
document.write( "...<BR>\n" );
document.write( "m.ananth@hotmail.ca </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );