document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=834235>Question 834235</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Jeff and kirk can build a 75 ft retaining wall together in 7 hours because Jeff has more experience he can build alone in two hours quicker than kirk. how long can it take kirk to build the wall alone? round to the nearest minute.<BR>\n" );
document.write( "thank you I am so stuck on this question I don't know what to do  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #502925 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=502925\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Jeff and kirk can build a 75 ft retaining wall together in 7 hours<BR>\n" );
document.write( " because Jeff has more experience he can build it alone in two hours quicker than kirk.<BR>\n" );
document.write( " how long can it take kirk to build the wall alone? round to the nearest minute.<BR>\n" );
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document.write( "Let t = time required by Jeff to build the wall<BR>\n" );
document.write( "then<BR>\n" );
document.write( "(t+2) = time required by Kirk<BR>\n" );
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document.write( "Let the completed job = 1 (a completed wall)<BR>\n" );
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document.write( "Each will do a fraction of the wall, the two fractions add up to 1<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7%2Ft ALIGN=MIDDLE  ALT=\"7%2Ft\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7%2F%28%28t%2B2%29%29 ALIGN=MIDDLE  ALT=\"7%2F%28%28t%2B2%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 1<BR>\n" );
document.write( "multiply by t(t+2), to clear the denominators, resulting in:<BR>\n" );
document.write( "7(t+2) + 7t = t(t+2)<BR>\n" );
document.write( "7t + 14 + 7t = t^2 + 2t<BR>\n" );
document.write( "14t + 14 = t^2 + 2t<BR>\n" );
document.write( "A quadratic equation<BR>\n" );
document.write( "0 = t^2 + 2t - 14t - 14<BR>\n" );
document.write( "t^2 - 12t - 14 = 0 <BR>\n" );
document.write( "Using the quadratic formula, the reasonable approx answer<BR>\n" );
document.write( "t = 13.071 hrs<BR>\n" );
document.write( "Kirk takes 2 hrs longer, therefore<BR>\n" );
document.write( "15.071 hrs for Kirk<BR>\n" );
document.write( "Find the hrs and minutes<BR>\n" );
document.write( "15 + ..071(60) = 15 hrs 4 minutes<BR>\n" );
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document.write( "Did this make sense to you?<BR>\n" );
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