document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=265461>Question 265461</A>: <I><SPAN STYLE=\"word-break: break-all;\"> To get to his parents' house, John must travel at a speed of 60 mph on land and then use a motorboat that travels at a speed of 20 mph in still water. John goes by land to a dock and then travels on a river against a current of 4 mph. He reaches his parent's home in 4.5 hours. The return trip takes him 3.5 hours. How far do his parents live from his house? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #195239 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=195239\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> To get to his parents' house, John must travel at a speed of 60 mph on land and then use a motorboat that travels at a speed of 20 mph in still water.<BR>\n" );
document.write( " John goes by land to a dock and then travels on a river against a current of 4 mph. <BR>\n" );
document.write( "He reaches his parent's home in 4.5 hours. <BR>\n" );
document.write( "The return trip takes him 3.5 hours.<BR>\n" );
document.write( " How far do his parents live from his house?<BR>\n" );
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document.write( "Let c = car distance<BR>\n" );
document.write( "Let b = boat distance<BR>\n" );
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document.write( "Write a time equation for each way, time = dist/speed<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=c%2F60 ALIGN=MIDDLE  ALT=\"c%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b%2F%28%2820-4%29%29 ALIGN=MIDDLE  ALT=\"b%2F%28%2820-4%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 4.5<BR>\n" );
document.write( "and<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=c%2F60 ALIGN=MIDDLE  ALT=\"c%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b%2F%28%2820%2B4%29%29 ALIGN=MIDDLE  ALT=\"b%2F%28%2820%2B4%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 3.5<BR>\n" );
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document.write( "Which is:<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=c%2F60 ALIGN=MIDDLE  ALT=\"c%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b%2F16 ALIGN=MIDDLE  ALT=\"b%2F16\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 4.5; use elimination on these two equations<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=c%2F60 ALIGN=MIDDLE  ALT=\"c%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b%2F24 ALIGN=MIDDLE  ALT=\"b%2F24\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 3.5<BR>\n" );
document.write( "-----------------------------------subtraction eliminates c/60 & we have:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b%2F16 ALIGN=MIDDLE  ALT=\"b%2F16\"   DISABLED_style= \"max-width:90%; height:auto;\" > - <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b%2F24 ALIGN=MIDDLE  ALT=\"b%2F24\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 1<BR>\n" );
document.write( "Multiply by 48, results<BR>\n" );
document.write( "3b - 2b = 48<BR>\n" );
document.write( "b = 48 mi by boat<BR>\n" );
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document.write( "Find the time to travel 48 mi up stream<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=48%2F16 ALIGN=MIDDLE  ALT=\"48%2F16\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 3 hrs<BR>\n" );
document.write( "then<BR>\n" );
document.write( "4.5 - 3 = 1.5 hrs by car<BR>\n" );
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document.write( "Find the distance by car: <BR>\n" );
document.write( "60*1.5 = 90 mi by car<BR>\n" );
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document.write( "Total dist: 90 + 48 = 138 miles from his house to his parents house.<BR>\n" );
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document.write( "Check solution by finding the time on the return trip<BR>\n" );
document.write( "90/60 + 48/24 = <BR>\n" );
document.write( "1.5 + 2 = 3.5 hrs </SPAN>\n" );
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