document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1205745>Question 1205745</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Trashia left Riverside, California, driving her motorhome north on Interstate 15 towards Salt Lake City at a speed of 40 miles per hour. Half an hour later, Karissa left Riverside in her car on the same route as Trashia, driving 60 miles per hour. Solve the system:\r<BR>\n" );
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document.write( "{(40 y=60 x),(y=x+1/2) :}\r<BR>\n" );
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document.write( "A. for x to find out how long it will take Karissa to<BR>\n" );
document.write( "catch up to Trashia.\r<BR>\n" );
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document.write( "B. What is the value of y the number of hours<BR>\n" );
document.write( "Trashia will have driven before Karissa catches up<BR>\n" );
document.write( "to her?   </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #842748 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13200)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=842748\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "40y = 60x<BR>\n" );
document.write( "y = x+1/2<br><BR>\n" );
document.write( "When one of the two equations tells you precisely what one variable is in terms of the other, the obvious choice for a solution method is substitution.  Replace \"y\" in the first equation with the equivalent expression \"x+1/2\".<br><BR>\n" );
document.write( "40(x+1/2) = 60x<BR>\n" );
document.write( "40x+20 = 60x<BR>\n" );
document.write( "20 = 20x<BR>\n" );
document.write( "x = 1<br><BR>\n" );
document.write( "A. x is the number of hours Karissa drives.  ANSWER: x = 1<br><BR>\n" );
document.write( "B. y is the number of hours Trashia drives.  ANSWER: y = x+1/2 = 1 1/2<br><BR>\n" );
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