document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=250787>Question 250787</A>: <I><SPAN STYLE=\"word-break: break-all;\"> you drive to the store at 20 mph and return by the same route at 30 mph.  Discounting the time spent at the store, what was your average speed? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #182658 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=182658\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> you drive to the store at 20 mph and return by the same route at 30 mph.<BR>\n" );
document.write( " Discounting the time spent at the store, what was your average speed?<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Let d = the one way distance<BR>\n" );
document.write( "then<BR>\n" );
document.write( "2d = the round trip<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Let a = average speed<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Write a time equation: time = dist/speed<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Time there + time back = time there & back<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F20 ALIGN=MIDDLE  ALT=\"d%2F20\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F30 ALIGN=MIDDLE  ALT=\"d%2F30\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%282d%29%2Fa ALIGN=MIDDLE  ALT=\"%282d%29%2Fa\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "multiply equation by 60a, results:<BR>\n" );
document.write( "3da + 2da = 60(2d)<BR>\n" );
document.write( "3da + 2da = 120d<BR>\n" );
document.write( ":<BR>\n" );
document.write( "divide thru by d, get rid of it<BR>\n" );
document.write( "3a + 2a = 120<BR>\n" );
document.write( "5a = 120<BR>\n" );
document.write( "a = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=120%2F5 ALIGN=MIDDLE  ALT=\"120%2F5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "a = 24 mph is the average speed<BR>\n" );
document.write( ":<BR>\n" );
document.write( ":<BR>\n" );
document.write( "See if that is true:<BR>\n" );
document.write( "Find the times if d = 60 mi<BR>\n" );
document.write( "60/20 + 60/30 = 120/24<BR>\n" );
document.write( "3 + 2 = 5\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );