document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=83179>Question 83179</A>: <I><SPAN STYLE=\"word-break: break-all;\"> i don't understand what to do with these two equations x+y=-1 and 2x-y=7 the directions say Estimate the solution of the linear system graphically. then check the solution algebraically.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #59695 by </B><A HREF=/tutors/aboutme.mpl?userid=checkley75><B>checkley75(3666)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=checkley75><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=59695\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> X+Y=-1, Y=-X-1 (RED LINE)<BR>\n" );
document.write( "2X-Y=7, -Y=-2X+7, Y=2X-7 (GREEN LINE)<BR>\n" );
document.write( "NOW SOLVE THESE 2 EQUATIONS BY SUBSTITUTING (-X-1) FOR Y IN THE SECOND EQUATION & SOLVE FOR X<BR>\n" );
document.write( "2X-(-X-1)=7<BR>\n" );
document.write( "2X+X+1=7<BR>\n" );
document.write( "3X=7-1<BR>\n" );
document.write( "3X=6<BR>\n" );
document.write( "X=6/3<BR>\n" );
document.write( "X=2 ANSWER.<BR>\n" );
document.write( "2+Y=-1<BR>\n" );
document.write( "Y=-1-2<BR>\n" );
document.write( "Y=-3 ANSWER.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+graph%28+300%2C+200%2C+-6%2C+5%2C+-10%2C+10%2C+y+=+-x+-1%2C+y+=+2x+-7%29+ ALIGN=MIDDLE  ALT=\"+graph%28+300%2C+200%2C+-6%2C+5%2C+-10%2C+10%2C+y+=+-x+-1%2C+y+=+2x+-7%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions y = -x -1 and y = 2x -7).  </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );