document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=237582>Question 237582</A>: <I><SPAN STYLE=\"word-break: break-all;\"> two towns are 80 km apart . kasia wants to drive from one town to the other in exactly one hour. for the first 30 minutes she drives at a rate of 60 km/h. the constant rate , in km/h, at which she must drive for the next 30 minutes to accomplish her goal is\r<BR>\n" );
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document.write( "(a) 20 (b) 40 (c) 50 (d) 80 (e) 100 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #174756 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=174756\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> distance = rate * time\r<BR>\n" );
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document.write( "t = 1<BR>\n" );
document.write( "d = 80 km\r<BR>\n" );
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document.write( "first part of the trip, rate * time was .5 * 60<BR>\n" );
document.write( "second part of the trip, rate * time will be .5 * x\r<BR>\n" );
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document.write( "add the parts together to get the total trip.\r<BR>\n" );
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document.write( ".5 * 60 + .5 * x = 80\r<BR>\n" );
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document.write( "30 + .5x = 80\r<BR>\n" );
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document.write( "subtract 30 from both sides to get:\r<BR>\n" );
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document.write( ".5x = 50\r<BR>\n" );
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document.write( "divide both sides by .5 to get:\r<BR>\n" );
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document.write( "x = 100\r<BR>\n" );
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document.write( "confirm by plugging into the original equation to get:\r<BR>\n" );
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document.write( ".5 * 60 + .5 * 100 = 80\r<BR>\n" );
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document.write( "simlify to get:\r<BR>\n" );
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document.write( "30 + 50 = 80 confirming the answer for x is good.\r<BR>\n" );
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document.write( "looks like she will have to drive 100 km/h in order to achieve her goal of driving 80 km in exactly 1 hour.\r<BR>\n" );
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