document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=43392>Question 43392</A>: <I><SPAN STYLE=\"word-break: break-all;\"> please help.  solve by substitution:  y=2x<BR>\n" );
document.write( "                                    x-y=4 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #28401 by </B><A HREF=/tutors/aboutme.mpl?userid=benni1013><B>benni1013(206)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=benni1013><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=28401\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> y=2x<BR>\n" );
document.write( "x-y=4\r<BR>\n" );
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document.write( "We know that y=2x so where y is in the second equation we put in 2x for y<BR>\n" );
document.write( "x-2x=4==>-x=4==>x=-4 </SPAN>\n" );
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