document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=125702>Question 125702</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I not sure how to write the equation for this one the one i did was wrong.\r<BR>\n" );
document.write( "\n" );
document.write( "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?\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #92094 by </B><A HREF=/tutors/aboutme.mpl?userid=scott8148><B>scott8148(6628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=scott8148><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=scott8148><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=92094\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the land part of the trip is the same, coming or going, so concentrate on the water\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "distance equals rate times time __ it takes an hour longer to go upstream\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "let t=\"return time on water\" __ (20-4)(t+1)=(20+4)(t) __ 16t+16=24t __ 16=8t __ t=.5\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "so 12 mi [24(.5)] on water and 180 mi [60(3.5-.5)] on land </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );