document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=152452>Question 152452</A>: <I><SPAN STYLE=\"word-break: break-all;\"> After 5 hours of house painting, Jess asked the assistance of Jon. Together, they finished the job in 4 more hours. Had Jon joined in an hour after Jess started working, the job would have been finished in 7 hours. How long would it have taken Jess to paint the house alone?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #112049 by </B><A HREF=/tutors/aboutme.mpl?userid=scott8148><B>scott8148(6628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=scott8148><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=scott8148><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=112049\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> let x=\"Jess time alone\" and y=\"Jon time alone\"\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "\"After 5 hours of house painting, Jess asked the assistance of Jon. Together, they finished the job in 4 more hours\"<BR>\n" );
document.write( "__ 9/x+4/y=1 __ 9y+4x=xy __ 4x=xy-9y __ 4x=y(x-9) __ 4x/(x-9)=y\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "\"Had Jon joined in an hour after Jess started working, the job would have been finished in 7 hours\"<BR>\n" );
document.write( "__ 8/x+7/y=1 __ 8y+7x=xy\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "substituting __ 8[4x/(x-9)]+7x=x[4x/(x-9)] __ multiplying by x-9 __ 32x+7x^2-63x=4x^2\r<BR>\n" );
document.write( "\n" );
document.write( "subtracting 4x^2 __ 3x^2-31x=0 __ factoring __ x(3x-31)=0\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "x=0 __ not realistic\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "3x-31=0 __ x=31/3 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );