document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=130320>Question 130320</A>: <I><SPAN STYLE=\"word-break: break-all;\"> i am absolutly confused on this question ive tried several different angles: \r<BR>\n" );
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document.write( "5x+2y+z=-11<BR>\n" );
document.write( "2x-3y-z= 17<BR>\n" );
document.write( "7x+y2+z= -4 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #95187 by </B><A HREF=/tutors/aboutme.mpl?userid=ilana><B>ilana(307)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ilana><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=95187\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You have 3 equations, call them A, B, and C.  First, combine A and B, eliminating z, to get an equation with x and y.  Then combine B and C, again eliminating z, to get another equation with x and y.  Then you will have a system with 2 equations and 2 variables, which you should know how to solve already.<BR>\n" );
document.write( "Adding A and B gives 7x-y=6 (call this D).  Adding B and C gives 9x-y=13 (call this E).  Change equation D to y=7x-6.  Now plug that y into E to get 9x-(7x-6)=13, so 2x+6=13, so 2x=7, so x=3.5.  plug that back into D to get y=7(3.5)-6=24.5-6 =18.5.  Using equation B, z=2x-3y-17=2(3.5)-3(18.5)-17= 7-55.5-17= -48.5-17=-65.5<BR>\n" );
document.write( "So (x, y, z)=(3.5, 18.5, -65.5). </SPAN>\n" );
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