document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=497435>Question 497435</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Henry and Irene working together can wash all the windows of their house in 1 h 24 min. Working alone, it takes Henry 4 1/2 h more than Irene to do the job. How long does it take each person working alone to wash all the windows? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #336730 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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=336730\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Henry and Irene working together can wash all the windows of their house in 1 h 24 min. Working alone, it takes Henry 4 1/2 h more than Irene to do the job. How long does it take each person working alone to wash all the windows?<BR>\n" );
document.write( "**<BR>\n" );
document.write( "let x=hours Irene takes to do the job alone<BR>\n" );
document.write( "1/x=Irene's work rate<BR>\n" );
document.write( "x+4.5=hours Henry takes to do the job alone<BR>\n" );
document.write( "1/(x+4.5)=Henry's work rate<BR>\n" );
document.write( "1 hr and 24 min=1.4 hr=Irene and Henry working together to do the job<BR>\n" );
document.write( "1/1.4=Their work rate working together<BR>\n" );
document.write( "..<BR>\n" );
document.write( "sum of individual work rates=work rate when working together<BR>\n" );
document.write( "1/x+1/(x+4.5)=1/1.4<BR>\n" );
document.write( "LCD:(x)(x+4.5)(1.4)<BR>\n" );
document.write( "(x+4.5)(1.4)+1.4x=(x)(x+4.5)<BR>\n" );
document.write( "1.4x+6.3+1.4x=x^2+4.5x<BR>\n" );
document.write( "x^2+1.7x-6.3=0<BR>\n" );
document.write( "solve by quadratic formula as follows:<BR>\n" );
document.write( "..<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "..<BR>\n" );
document.write( "a=1, b=1.7, c=-6.3<BR>\n" );
document.write( "x=[-1.7±&#8730;(1.7^2-4*1*-6.3)]2*1<BR>\n" );
document.write( "x=[-1.7±&#8730;28.09]/2<BR>\n" );
document.write( "x=(-1.7±5.3)/2<BR>\n" );
document.write( "x=-7/2=-3.5 (reject, x>0)<BR>\n" );
document.write( "or <BR>\n" );
document.write( "x=3.6/2=1.8<BR>\n" );
document.write( "ans:<BR>\n" );
document.write( "It takes Irene 1.8 hrs or 1 hr and 45 minutes to do the job alone.<BR>\n" );
document.write( "Henry takes 4.5 hrs longer or 6.3 hr or 6 hrs and 18 minutes to do the job alone. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );