document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=247408>Question 247408</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Donna drove half the distance of a trip at 40 mi/h. At what speed would she have to drive for the rest of the distance so that the average speed for the entire trip would be 45 mi/h? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #180512 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=180512\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  half the distance of a trip at 40 mi/h.<BR>\n" );
document.write( " At what speed would she have to drive for the rest of the distance so that the average speed for the entire trip would be 45 mi/h?<BR>\n" );
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document.write( "Let s = speed required on the 2nd half to average 45 mph for the trip<BR>\n" );
document.write( "Let d = total distance of the trip<BR>\n" );
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document.write( "Write time equation; time = dist/speed<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=.5d%2F40 ALIGN=MIDDLE  ALT=\".5d%2F40\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=.5d%2Fs ALIGN=MIDDLE  ALT=\".5d%2Fs\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F45 ALIGN=MIDDLE  ALT=\"d%2F45\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "multiply equation by 360s to get rid of the denominator:<BR>\n" );
document.write( "9s(.5d) + 360(.5d) = 8s(d)<BR>\n" );
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document.write( "4.5sd + 180d = 8sd<BR>\n" );
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document.write( "Divide thru by d<BR>\n" );
document.write( "4.5s + 180 = 8s<BR>\n" );
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document.write( "180 = 8s - 4.5s<BR>\n" );
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document.write( "180 = 3.5s<BR>\n" );
document.write( "s = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=180%2F3.5 ALIGN=MIDDLE  ALT=\"180%2F3.5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "s = 51.43 mph<BR>\n" );
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document.write( " </SPAN>\n" );
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