document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=92240>Question 92240</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Solve the system by substitution.<BR>\n" );
document.write( "     3x – y = –7<BR>\n" );
document.write( "       x + y = –9<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #67073 by </B><A HREF=/tutors/aboutme.mpl?userid=checkley71><B>checkley71(8403)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=checkley71><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=67073\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> x+y=-9 or y=-x-9 now substitute.<BR>\n" );
document.write( "3x-(-x-9)=-7<BR>\n" );
document.write( "3x+x+9=-7<BR>\n" );
document.write( "4x=-7-9<BR>\n" );
document.write( "4x=-16<BR>\n" );
document.write( "x=-16/4<BR>\n" );
document.write( "x=-4 answer.<BR>\n" );
document.write( "-4+y=-9<BR>\n" );
document.write( "y=-9+4<BR>\n" );
document.write( "y=-5 answer.<BR>\n" );
document.write( "proof<BR>\n" );
document.write( "3*-4-(-5)=-7<BR>\n" );
document.write( "-12+5=-7<BR>\n" );
document.write( "-7=-7 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );