document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1010694>Question 1010694</A>: <I><SPAN STYLE=\"word-break: break-all;\"> John paints a house 9 hrs longer than frank. Together they can pain it in 20 hrs. How long does it take frank to paint?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #626166 by </B><A HREF=/tutors/aboutme.mpl?userid=fractalier><B>fractalier(6550)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=fractalier><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=fractalier><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=626166\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Call the time it takes Frank, f.  Then John takes f+9.  The normal setup looks like this:<BR>\n" );
document.write( "t/A + t/B = 1<BR>\n" );
document.write( "Now plug in and get<BR>\n" );
document.write( "20/f + 20/(f+9) = 1<BR>\n" );
document.write( "Multiply by f(f+9) and get<BR>\n" );
document.write( "20(f+9) + 20f = f(f+9)<BR>\n" );
document.write( "20f + 180 + 20f = f^2 + 9f<BR>\n" );
document.write( "Now collect like terms and solve...we get<BR>\n" );
document.write( "f^2 - 31f - 180 = 0<BR>\n" );
document.write( "(f - 36)(f + 5) = 0<BR>\n" );
document.write( "f = 36 hours<BR>\n" );
document.write( "f+9 = 45 hours </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );