document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1014193>Question 1014193</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The distance (in miles) traveled when driving at a certain speed s for 38 hours, then driving 13 miles/hour faster for another hour. Express the distance in terms of s </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #630541 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=630541\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> rate * time = distance\r<BR>\n" );
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document.write( "rate and speed mean the same thing in this type of problem.\r<BR>\n" );
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document.write( "therefore, rate * time = distance becomes s * time = distance.\r<BR>\n" );
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document.write( "the problem states that you are traveling at a speed of s miles per hour for 38 hours and then at a speed of 13 miles per hour faster than s for another hour.\r<BR>\n" );
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document.write( "if you let d1 = the distance at s miles per hour for 38 miles and d2 = the distance at s + 13 miles per hour for 1 hour, then you get d = d1 + d2.\r<BR>\n" );
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document.write( "this results in:\r<BR>\n" );
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document.write( "d = d1 + d2<BR>\n" );
document.write( "d1 = 38s<BR>\n" );
document.write( "d2 = 1*(s+13) = s+13<BR>\n" );
document.write( "d = d1 + d2 = 38s + s + 13\r<BR>\n" );
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document.write( "combine like terms to get d = 39s + 13.\r<BR>\n" );
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document.write( "that's your solution.\r<BR>\n" );
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document.write( "confirm by assigning a random value of speed to replace.\r<BR>\n" );
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document.write( "i chose 40 miles per hour.\r<BR>\n" );
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document.write( "s = 40 miles per hour.<BR>\n" );
document.write( "d = 39s + 13 becomes d = 39*40 + 13 which becomes d = 1573.\r<BR>\n" );
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document.write( "d also equals d1 + d2.<BR>\n" );
document.write( "d1 = 38s<BR>\n" );
document.write( "d2 = s + 13\r<BR>\n" );
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document.write( "when s = 40, this becomes:\r<BR>\n" );
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document.write( "d1 = 38 * 40 = 1520<BR>\n" );
document.write( "d2 = 40 + 13 = 53<BR>\n" );
document.write( "d1 + d2 = 1520 + 53 = 1573 = d\r<BR>\n" );
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document.write( "you get the same answer with both formulas, so the solution looks good.<BR>\n" );
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