document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=103558>Question 103558</A>: <I><SPAN STYLE=\"word-break: break-all;\"> x + y = 12<BR>\n" );
document.write( "    y = 2x<BR>\n" );
document.write( "HELP </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #75288 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=75288\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> One of the way to solve linear equations is to substitute.\r<BR>\n" );
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document.write( "In this case, you're given y=2x, so it's ready for substitution.\r<BR>\n" );
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document.write( "x+y=12 is the other equation, so substitute the value of y.\r<BR>\n" );
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document.write( "x+2x=12\r<BR>\n" );
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document.write( "Collecting like terms:<BR>\n" );
document.write( "3x = 12<BR>\n" );
document.write( "Dividing through by 3:<BR>\n" );
document.write( "x = 4<BR>\n" );
document.write( "Now go back to first equation: x + y = 12.<BR>\n" );
document.write( "We now know x = 4, so it becomes:<BR>\n" );
document.write( "4 + y = 12<BR>\n" );
document.write( "Subtracting 4 from both sides:<BR>\n" );
document.write( "y = 8.<BR>\n" );
document.write( "ALWAYS check.<BR>\n" );
document.write( "In this case, does y = 2x?<BR>\n" );
document.write( "y = 2x<BR>\n" );
document.write( "8 = 2*4<BR>\n" );
document.write( "8 = 8.<BR>\n" );
document.write( "Check! </SPAN>\n" );
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