document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=121110>Question 121110</A>: <I><SPAN STYLE=\"word-break: break-all;\"> SUBSTITUTION AND ELIMINATION<BR>\n" );
document.write( "1. 2X+Y-3Z=0<BR>\n" );
document.write( "2. -2X+2Y+Z=-7<BR>\n" );
document.write( "3. X-4Y-3Z=7\r<BR>\n" );
document.write( "\n" );
document.write( "TRYING TO SOLVE FOR X,Y,Z<BR>\n" );
document.write( " TRIED ELIMINATING X BY ADDING 1&2  WHICH GAVE ME 3Y-2Z=-7 ANS. IS NOW NEW ANS.4  THEN TRIED TO SOLVE BY ELIMINATING X AGAIN BY USING1&3 WHICH CHANGED NO.3 AFTER  MULT. -2(X-4Y-3Z=7 WHICH GAVE ME -2X+4Y+6Z=-14 WHICH IN TURN GAVE ME NEW ANS.5 NOW- THIS IS WHERE I GET CONFUSED DO I SOLVE FOR EITHER Y OR Z IN NEW ANSWERS 4&5 BY FINDING NEW COMMON FACTOR, THEN SOLVING?  OR DO I PLACE ANY OF THE ANSWERS INTO ANOTHER PROBLEM?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #88860 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=88860\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  2X+ Y-3Z =0<BR>\n" );
document.write( "-2X+2Y+Z =-7<BR>\n" );
document.write( "  X-4Y-3Z =7 <BR>\n" );
document.write( "-------------------<BR>\n" );
document.write( "Put #3 in the #1 position:<BR>\n" );
document.write( " X-4Y-3Z =7<BR>\n" );
document.write( "2X+ Y-3Z =0<BR>\n" );
document.write( "-2X+2Y+Z =-7<BR>\n" );
document.write( "---------------<BR>\n" );
document.write( "Subtract twicd #1 from #2; Add twice #1 to #3 to get:<BR>\n" );
document.write( " X-4Y-3Z =7<BR>\n" );
document.write( " 0+9y+3Z =-14<BR>\n" );
document.write( " 0-6Y-5Z = 7<BR>\n" );
document.write( "-----------------<BR>\n" );
document.write( "Add #3 to #2 to get:<BR>\n" );
document.write( " X-4Y-3Z =7<BR>\n" );
document.write( " 0+3y-2Z =-7<BR>\n" );
document.write( " 0-6Y-5Z = 7<BR>\n" );
document.write( "----------------<BR>\n" );
document.write( "Add twice #2 to #3 to get:<BR>\n" );
document.write( " X-4Y-3Z = 7<BR>\n" );
document.write( " 0+3y-2Z =-7<BR>\n" );
document.write( " 0+ 0-9Z =-7<BR>\n" );
document.write( "----------------<BR>\n" );
document.write( "Divide thru #3 by -9 to get:<BR>\n" );
document.write( "X-4Y-3Z = 7<BR>\n" );
document.write( " 0+3y-2Z =-7<BR>\n" );
document.write( " 0+ 0+Z = 7/9<BR>\n" );
document.write( "----------------<BR>\n" );
document.write( "Substitute that value of Z into #2 to solve for Y.<BR>\n" );
document.write( "Then substitute the Z value and the Y value into #1 to solve for X.<BR>\n" );
document.write( "-----------------------<BR>\n" );
document.write( "I get :<BR>\n" );
document.write( "X = 2.0741<BR>\n" );
document.write( "Y = -1.8148 <BR>\n" );
document.write( "Z = 0.7778= 7/9\r<BR>\n" );
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document.write( "=====================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.\r<BR>\n" );
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document.write( "   </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );