document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=501029>Question 501029</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Mr. jenkins can dig a ditch in one hour less time than his son. working together they can do the job in 2/3 hrs. how long does it take mr. jenkins to do the job alone? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #338394 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=338394\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Mr. jenkins can dig a ditch in one hour less time than his son.<BR>\n" );
document.write( " working together they can do the job in 2/3 hrs.<BR>\n" );
document.write( " how long does it take mr. jenkins to do the job alone?<BR>\n" );
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document.write( "Let t = time for Mr. J to do the job alone<BR>\n" );
document.write( "Let the completed job = 1; (a dug ditch)<BR>\n" );
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document.write( "Let's do this in minutes<BR>\n" );
document.write( "2/3 hr = 40 min<BR>\n" );
document.write( "and<BR>\n" );
document.write( "(t+60) = time required by the son alone<BR>\n" );
document.write( ";<BR>\n" );
document.write( "A typical shared work equation<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=40%2Ft ALIGN=MIDDLE  ALT=\"40%2Ft\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=40%2F%28%28t%2B60%29%29 ALIGN=MIDDLE  ALT=\"40%2F%28%28t%2B60%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 1<BR>\n" );
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document.write( "Multiply by t(t+60); results<BR>\n" );
document.write( "40(t+60) + 40t = t(t+60)<BR>\n" );
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document.write( "40t + 2400 + 40t = t^2 + 60t<BR>\n" );
document.write( "80t + 2400 = t^2 + 60t<BR>\n" );
document.write( "Arrange as a quadratic equation<BR>\n" );
document.write( "t^2 + 60t - 80t - 2400 = 0<BR>\n" );
document.write( "t^2 - 20t - 2400 = 0<BR>\n" );
document.write( "factors to<BR>\n" );
document.write( "(t-60)(t+40) = 0<BR>\n" );
document.write( "positive solution<BR>\n" );
document.write( "t = 60 min or 1 hr for Mr. J to do the job<BR>\n" );
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document.write( "you can check this in the original equation<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=40%2F60 ALIGN=MIDDLE  ALT=\"40%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=40%2F%28%2860%2B60%29%29 ALIGN=MIDDLE  ALT=\"40%2F%28%2860%2B60%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > =  </SPAN>\n" );
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