document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=142242>Question 142242</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Joe cleans his room in 7 hours.  With his mom, it takes them 3 hours.  How long does it take mom alone? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #103575 by </B><A HREF=/tutors/aboutme.mpl?userid=checkley77><B>checkley77(12844)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=checkley77><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=103575\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 7*x/(7+x)=3<BR>\n" );
document.write( "7x=3(7+x)<BR>\n" );
document.write( "7x=21+3x<BR>\n" );
document.write( "7x-3x=21<BR>\n" );
document.write( "4x=21<BR>\n" );
document.write( "x=21/4<BR>\n" );
document.write( "x=5.25 hours for the mom cleaning the room alone.<BR>\n" );
document.write( "Proof:<BR>\n" );
document.write( "7*5.25/(7+5.25)=3<BR>\n" );
document.write( "36.75/12.25=3<BR>\n" );
document.write( "3=3 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );