document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=894749>Question 894749</A>: <I><SPAN STYLE=\"word-break: break-all;\"> It takes Jack 15 hours longer to drain a basement than Jill. If they work together, it takes 4 hours to drain a basement. How long does it take for each person to working alone? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #542293 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=542293\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> It takes Jack 15 hours longer to drain a basement than Jill. If they work together, it takes 4 hours to drain a basement. How long does it take for each person to working alone?<BR>\n" );
document.write( "Jack DATA:<BR>\n" );
document.write( "time = x + 15 hrs/job ; rate = 1/(x+15) job/hr<BR>\n" );
document.write( "----<BR>\n" );
document.write( "Jill DATA:<BR>\n" );
document.write( "time = x hrs/job ; rate = 1/x job/hr<BR>\n" );
document.write( "------------------------<BR>\n" );
document.write( "Together DATA:<BR>\n" );
document.write( "time = 4 hrs/job ; rate = 1/4 job/hr<BR>\n" );
document.write( "------------------------------------------<BR>\n" );
document.write( "Equation:<BR>\n" );
document.write( "rate + rate = together rate<BR>\n" );
document.write( "1/x + 1/(x+15) = 1/4<BR>\n" );
document.write( "------------------------------<BR>\n" );
document.write( "Multiply thru by 4x(x+15) to get::<BR>\n" );
document.write( "4(x+15) + 4x = x(x+15)<BR>\n" );
document.write( "4x + 60 + 4x = x^2 + 15x<BR>\n" );
document.write( "----------<BR>\n" );
document.write( "x^2 + 7x - 60 = 0<BR>\n" );
document.write( "------<BR>\n" );
document.write( "(x+12)(x-5) = 0<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "Positive solution:<BR>\n" );
document.write( "x = 5 hrs (Jill's time)<BR>\n" );
document.write( "x+15 = 20 hrs (Jack's time)<BR>\n" );
document.write( "------------------<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "------------------ </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );