document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=322767>Question 322767</A>: <I><SPAN STYLE=\"word-break: break-all;\"> substition<BR>\n" );
document.write( "x+y=12<BR>\n" );
document.write( "x-4y=-8 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #231046 by </B><A HREF=/tutors/aboutme.mpl?userid=jessica43><B>jessica43(140)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jessica43><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=231046\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> First you want to rewrite the first equation and then plug it into the second equation.<BR>\n" );
document.write( "x + y = 12 can be rewritten as x = 12 - y (subtract y from each side).<BR>\n" );
document.write( "Now plug this new value of x into the second equation and solve for y:<BR>\n" );
document.write( "x-4y = -8<BR>\n" );
document.write( "(12-y)- 4y = -8<BR>\n" );
document.write( "12 - y - 4y = -8<BR>\n" );
document.write( "12 - 5y = -8<BR>\n" );
document.write( "-5y = -20<BR>\n" );
document.write( "y = 4<BR>\n" );
document.write( "Plug this value into the first equation to find x:<BR>\n" );
document.write( "x + y = 12<BR>\n" );
document.write( "x + 4 = 12<BR>\n" );
document.write( "x= 8<BR>\n" );
document.write( "So y=4 and x=8. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );