document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=31173>Question 31173</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0131449729/algebrahomeworkh>Into Algebra</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> A car travels 90 miles in the same time that car travelins 10 miles per hour slower travels 60 miles. Find the speed of each car. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #17875 by </B><A HREF=/tutors/aboutme.mpl?userid=mbarugel><B>mbarugel(146)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=mbarugel><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=17875\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Hello!<BR>\n" );
document.write( "Let's call X to the speed of the fast car. The time needed for a car going at X miles per hour (mph) to travel 90 miles is:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=90%2FX ALIGN=MIDDLE  ALT=\"90%2FX\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "[for example, if it were going at 45 mph, it would need 2 hours to travel 90 miles]\r<BR>\n" );
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document.write( "The other car travles 10 mph slower; that is, at <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=X-10 ALIGN=MIDDLE  ALT=\"X-10\"   DISABLED_style= \"max-width:90%; height:auto;\" > mph. The time it takes this car to travel 60 miles would then be:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=60%2F%28X-10%29 ALIGN=MIDDLE  ALT=\"60%2F%28X-10%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "But we also know that these times are equal. So we have the equation:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=90%2FX+=+60%2F%28X-10%29 ALIGN=MIDDLE  ALT=\"90%2FX+=+60%2F%28X-10%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Cross-multiplying:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=90X+-+900+=+60X ALIGN=MIDDLE  ALT=\"90X+-+900+=+60X\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30X+=+900 ALIGN=MIDDLE  ALT=\"30X+=+900\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=X+=+30 ALIGN=MIDDLE  ALT=\"X+=+30\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "The fast car travels at 30 mph; the other one, at 20 mph.\r<BR>\n" );
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document.write( "I hope this helps!\r<BR>\n" );
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document.write( "Get more answers at <a  rel=nofollow HREF=http://www.onlinemathanswers.com>Online Math Answers.com</a>!<BR>\n" );
document.write( " </SPAN>\n" );
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