document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=902629>Question 902629</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Jake drives a tractor from one town to another, a distance of 130 kilometers. He drives 9 kilometers per hour faster on the return trip, cutting 1 hour off the time. How fast does he drive each way? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #547425 by </B><A HREF=/tutors/aboutme.mpl?userid=Jc0110><B>Jc0110(165)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Jc0110><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=547425\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let speed = v while time = t.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=Speed=Distance%2FTime ALIGN=MIDDLE  ALT=\"Speed=Distance%2FTime\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Depart trip: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v=130%2Ft ALIGN=MIDDLE  ALT=\"v=130%2Ft\"   DISABLED_style= \"max-width:90%; height:auto;\" > --> Equation 1<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=130%2Fv ALIGN=MIDDLE  ALT=\"t=130%2Fv\"   DISABLED_style= \"max-width:90%; height:auto;\" > --> Equation 2 ... Substitute into Equation 3.<BR>\n" );
document.write( "Return trip: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v%2B9=130%2F%28t-1%29 ALIGN=MIDDLE  ALT=\"v%2B9=130%2F%28t-1%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > --> Equation 3<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v%2B9=130%2F%28%28130%2Fv%29-1%29 ALIGN=MIDDLE  ALT=\"v%2B9=130%2F%28%28130%2Fv%29-1%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v%2B9=130%2F%28%28130-v%29%2Fv%29 ALIGN=MIDDLE  ALT=\"v%2B9=130%2F%28%28130-v%29%2Fv%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v%2B9=130%2A%28v%2F%28130-v%29%29 ALIGN=MIDDLE  ALT=\"v%2B9=130%2A%28v%2F%28130-v%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v%2B9=130v%2F%28130-v%29 ALIGN=MIDDLE  ALT=\"v%2B9=130v%2F%28130-v%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28v%2B9%29%28130-v%29=130v ALIGN=MIDDLE  ALT=\"%28v%2B9%29%28130-v%29=130v\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=130v-v%5E2%2B1170-9v=130v ALIGN=MIDDLE  ALT=\"130v-v%5E2%2B1170-9v=130v\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v%5E2%2B130v-130v%2B9v-1170=0 ALIGN=MIDDLE  ALT=\"v%5E2%2B130v-130v%2B9v-1170=0\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v%5E2%2B9v-1170=0 ALIGN=MIDDLE  ALT=\"v%5E2%2B9v-1170=0\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28v%2B39%29%28v-30%29=0 ALIGN=MIDDLE  ALT=\"%28v%2B39%29%28v-30%29=0\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v=-39 ALIGN=MIDDLE  ALT=\"v=-39\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v=30 ALIGN=MIDDLE  ALT=\"v=30\"   DISABLED_style= \"max-width:90%; height:auto;\" > ... Substitute both <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v=-39 ALIGN=MIDDLE  ALT=\"v=-39\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v=30 ALIGN=MIDDLE  ALT=\"v=30\"   DISABLED_style= \"max-width:90%; height:auto;\" > into Equation 2.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=130%2F-39 ALIGN=MIDDLE  ALT=\"t=130%2F-39\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=130%2F30 ALIGN=MIDDLE  ALT=\"t=130%2F30\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=-10%2F3 ALIGN=MIDDLE  ALT=\"t=-10%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" > hours or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=13%2F3 ALIGN=MIDDLE  ALT=\"t=13%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" > hours<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=13%2F3 ALIGN=MIDDLE  ALT=\"t=13%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" > hours is acceptable, while <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=-10%2F3 ALIGN=MIDDLE  ALT=\"t=-10%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" > hours is unacceptable because time cannot be in negative.<BR>\n" );
document.write( "Substitute <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=13%2F3 ALIGN=MIDDLE  ALT=\"t=13%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" > into Equation 1 and 3 for speed of depart trip and speed of return trip respectively.<BR>\n" );
document.write( "------------------------------------------------------------------------<BR>\n" );
document.write( "Depart trip: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v=130%2F%2813%2F3%29 ALIGN=MIDDLE  ALT=\"v=130%2F%2813%2F3%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Speed of depart trip, v=<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30 ALIGN=MIDDLE  ALT=\"30\"   DISABLED_style= \"max-width:90%; height:auto;\" >km per hour<BR>\n" );
document.write( "Therefore, speed of depart trip is 30 km per hour.<BR>\n" );
document.write( "Return trip: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=v%2B9=130%2F%28%2813%2F3%29-1%29 ALIGN=MIDDLE  ALT=\"v%2B9=130%2F%28%2813%2F3%29-1%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Speed of return trip, v+9=<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=130%2F%28%2813%2F3%29-1%29 ALIGN=MIDDLE  ALT=\"130%2F%28%2813%2F3%29-1%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Speed of return trip, v+9=<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=39 ALIGN=MIDDLE  ALT=\"39\"   DISABLED_style= \"max-width:90%; height:auto;\" >km per hour<BR>\n" );
document.write( "Therefore, speed of return trip is 39 km per hour. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );