document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=446733>Question 446733</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Ben has to go to soccer practice. He and his brother leave their house and drive to the school averaging 50 miles per hour. On the way home they averaged only 30 miles per hour due to traffic. What was the average speed of the trip? The answer is NOT 40 miles per hour. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #307652 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=307652\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> He and his brother leave their house and drive to the school averaging 50 miles per hour.<BR>\n" );
document.write( " On the way home they averaged only 30 miles per hour due to traffic.<BR>\n" );
document.write( " What was the average speed of the trip? <BR>\n" );
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document.write( "Let a = average speed for the round trip<BR>\n" );
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document.write( "Let d = one-way distance to school<BR>\n" );
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document.write( "Write time equation: time = dist/speed<BR>\n" );
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document.write( "To time + return time = total time<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F50 ALIGN=MIDDLE  ALT=\"d%2F50\"   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 by 150a to clear the denominators<BR>\n" );
document.write( "150a*<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F50 ALIGN=MIDDLE  ALT=\"d%2F50\"   DISABLED_style= \"max-width:90%; height:auto;\" > + 150a*<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;\" > = 150a*<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( "cancel the denominators<BR>\n" );
document.write( "3a(d) + 5a(d) = 150(2d)<BR>\n" );
document.write( "Divide thru by d, we don't need that<BR>\n" );
document.write( "3a + 5a = 150(2)<BR>\n" );
document.write( "8a = 300<BR>\n" );
document.write( "a = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=300%2F8 ALIGN=MIDDLE  ALT=\"300%2F8\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "a = 37.5 mph is the average speed for the round trip<BR>\n" );
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document.write( "You can confirm this. Use a one-way dist of 150 mi<BR>\n" );
document.write( "150/50 + 150/30 = 300/37.5 </SPAN>\n" );
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