document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=430757>Question 430757</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Sam's Subaru travels 280 miles at a certain speed.  if the car had gone 5 mph faster, the trip would have taken 1 hour less.  find Sam's speed. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #299113 by </B><A HREF=/tutors/aboutme.mpl?userid=oberobic><B>oberobic(2304)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=oberobic><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=299113\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> d=rt<BR>\n" );
document.write( "d=280<BR>\n" );
document.write( "280 = rt<BR>\n" );
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document.write( "Going 5 mph faster makes the trip in 1 less hr, to cover the same distance.<BR>\n" );
document.write( "d = (r+5)(t-1)<BR>\n" );
document.write( "280 = (r+5)(t-1)<BR>\n" );
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document.write( "Since each = 280, then they have to = each other.<BR>\n" );
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document.write( "rt = (r+5)(t-1)<BR>\n" );
document.write( "Multiply through on the right side.<BR>\n" );
document.write( "rt = rt +5t -r - 5<BR>\n" );
document.write( "Subtract rt from both sides<BR>\n" );
document.write( "0 = 5t -r - 5<BR>\n" );
document.write( "Add r to both sides<BR>\n" );
document.write( "r = 5t-5<BR>\n" );
document.write( "Substitute back into the distance equation<BR>\n" );
document.write( "280 = (5t-5)*t<BR>\n" );
document.write( "Expand<BR>\n" );
document.write( "280 = 5t^2 -5t<BR>\n" );
document.write( "Subtract 280 from both sides<BR>\n" );
document.write( "0 = 5t^2 -5t - 280<BR>\n" );
document.write( "Equals are equal, so you can write it either way<BR>\n" );
document.write( "5t^2 -5t - 280 = 0<BR>\n" );
document.write( "Factor<BR>\n" );
document.write( "(5t-40)(t+7)=0<BR>\n" );
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document.write( "Inspect the solutions for applicability<BR>\n" );
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document.write( "5t = 40<BR>\n" );
document.write( "t = 8, is one solution<BR>\n" );
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document.write( "t = -7 is not a reasonable solution because we cannot have negative time<BR>\n" );
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document.write( "Substitute t=8 to find r<BR>\n" );
document.write( "280 = r*8<BR>\n" );
document.write( "Divide both sides by 8<BR>\n" );
document.write( "r = 280/8<BR>\n" );
document.write( "r = 35<BR>\n" );
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document.write( "Now check your work to see if the modified equation works<BR>\n" );
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document.write( "280 = (r+5)(t-1)<BR>\n" );
document.write( "280 = (35+5)(8-1)<BR>\n" );
document.write( "280 = (40)(7)<BR>\n" );
document.write( "True<BR>\n" );
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document.write( "Re-read the question to ensure you answer it.<BR>\n" );
document.write( "Sam's speed was 35 mph.<BR>\n" );
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document.write( "Done. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );