document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=388672>Question 388672</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A person drives with constant speed and after some time he sees a milestone with 2 digits. Then travels for 1 hours and sees the same 2 digits in reverse order. 1 hours later he sees that the milestone has the same 2 digits with a 0 between them. What is the speed of the car?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #275034 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=275034\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A person drives with constant speed and after some time he sees a milestone with 2 digits. <BR>\n" );
document.write( "Then travels for 1 hour and sees the same 2 digits in reverse order.<BR>\n" );
document.write( " 1 hours later he sees that the milestone has the same 2 digits with a 0 between them.<BR>\n" );
document.write( " What is the speed of the car?<BR>\n" );
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document.write( "Let x = the 1st digit on the first mile stone<BR>\n" );
document.write( "Let y = the 2nd digit <BR>\n" );
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document.write( "Let s = speed of the car<BR>\n" );
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document.write( "\"Then travels for 1 hour and sees the same 2 digits in reverse order.\"<BR>\n" );
document.write( "10x + y + 1s = 10y + x<BR>\n" );
document.write( "10x - x + s = 10y - y<BR>\n" );
document.write( "9x + s = 9y<BR>\n" );
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document.write( "\"1 hours later he sees that the milestone has the same 2 digits with a 0 between them.\"<BR>\n" );
document.write( "10y + x + s = 100x + y<BR>\n" );
document.write( "10y - y + s = 100x - x<BR>\n" );
document.write( "9y + s = 99x<BR>\n" );
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document.write( "Rearrange the above two equations for elimination<BR>\n" );
document.write( "9x - 9y + s = 0<BR>\n" );
document.write( "-99x+9y + s = 0<BR>\n" );
document.write( "----------------adding eliminates y<BR>\n" );
document.write( "-90x + 2s = 0<BR>\n" );
document.write( "2s = 90x<BR>\n" );
document.write( "s = 45x<BR>\n" );
document.write( "x has to equal 1, then s = 45 mph (If x=2 and s=90 mph, when added to<BR>\n" );
document.write( " a two digit milestone, could not be at another two digit milestone.)<BR>\n" );
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document.write( "Find y<BR>\n" );
document.write( "9x + s = 9y<BR>\n" );
document.write( "9(1) + 45 = 9y<BR>\n" );
document.write( "9 + 45 = 9y<BR>\n" );
document.write( "simplify divide by 9<BR>\n" );
document.write( "1 + 5 = y<BR>\n" );
document.write( "y = 6<BR>\n" );
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document.write( "Speed is 45 mph, x=1, y=6; 1st mile marker 16<BR>\n" );
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document.write( "Try this:<BR>\n" );
document.write( "1st milestone: 16<BR>\n" );
document.write( "travel one hr +45<BR>\n" );
document.write( "2nd milestone: 61<BR>\n" );
document.write( "travel one hr:+45<BR>\n" );
document.write( "3rd milestone:106<BR>\n" );
document.write( " <BR>\n" );
document.write( " </SPAN>\n" );
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