document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=177594>Question 177594</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0321370910/algebrahomeworkh>College Algebra</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> Junior drove his rig on the Interstate 10 from San Antonio to El Paso. At the halfway point he noticed that he had been averaging 80mph, while his company requires his average speed to be 60mph. What must be his speed for the last half of the trip so that he will average 60mph for the entire trip.<BR>\n" );
document.write( "The book also gives this hint: The distance from San Antonio to El Paso is irrelevant. Use D or simply make up a distance. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #132653 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=132653\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Junior drove his rig on the Interstate 10 from San Antonio to El Paso. At the<BR>\n" );
document.write( " halfway point he noticed that he had been averaging 80 mph, while his company<BR>\n" );
document.write( " requires his average speed to be 60 mph. What must be his speed for the last<BR>\n" );
document.write( " half of the trip so that he will average 60mph for the entire trip.<BR>\n" );
document.write( ";<BR>\n" );
document.write( "let s = speed required on the last half of the trip<BR>\n" );
document.write( "let d = half the distance of the trip<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Write a time equation: Time = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=dist%2Fspeed ALIGN=MIDDLE  ALT=\"dist%2Fspeed\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( ":<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F80 ALIGN=MIDDLE  ALT=\"d%2F80\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2Fs ALIGN=MIDDLE  ALT=\"d%2Fs\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%282d%29%2F60 ALIGN=MIDDLE  ALT=\"%282d%29%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( ":<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28sd%2B80d%29%2F%2880s%29 ALIGN=MIDDLE  ALT=\"%28sd%2B80d%29%2F%2880s%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%282d%29%2F60 ALIGN=MIDDLE  ALT=\"%282d%29%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "cross multiply<BR>\n" );
document.write( "60(sd + 80d) = 80s(2d)<BR>\n" );
document.write( ":<BR>\n" );
document.write( "60sd + 4800d = 160sd<BR>\n" );
document.write( ":<BR>\n" );
document.write( "divide eq by d<BR>\n" );
document.write( "60s + 4800 = 160s<BR>\n" );
document.write( ":<BR>\n" );
document.write( "4800 = 160s - 60s<BR>\n" );
document.write( ":<BR>\n" );
document.write( "4800 = 100s<BR>\n" );
document.write( "s = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4800%2F100 ALIGN=MIDDLE  ALT=\"4800%2F100\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "s = 48 mph to average out to 60 mph<BR>\n" );
document.write( ":<BR>\n" );
document.write( ";<BR>\n" );
document.write( "check solution using 600 mi from SA to EP (2d)<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=300%2F80 ALIGN=MIDDLE  ALT=\"300%2F80\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=300%2F48 ALIGN=MIDDLE  ALT=\"300%2F48\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28600%29%2F60 ALIGN=MIDDLE  ALT=\"%28600%29%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( " 3.75 + 6.25 = 10<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );