document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=741556>Question 741556</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Solve the system of 3 linear equations containing 3 unknowns. I can't bring myself to understand how to do these. Please provide steps; it would be greatly appreciated! \r<BR>\n" );
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document.write( "x-y=5<BR>\n" );
document.write( "5x-8z=35<BR>\n" );
document.write( "5y+z=10 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #452060 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39618)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><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=452060\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Do you want to use matrix or use substitution?  \r<BR>\n" );
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document.write( "Try substitution.  Solve the first equation for x:<BR>\n" );
document.write( "x=5+y.\r<BR>\n" );
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document.write( "Substitute this expression for x into the second equation:<BR>\n" );
document.write( "5x-8z=35<BR>\n" );
document.write( "5(5+y)-8z=35<BR>\n" );
document.write( "25+5y-8z=35<BR>\n" );
document.write( "5y-8z=10\r<BR>\n" );
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document.write( "You still have the last equation which is in variables y and z, so you have your choice of either taking the one you just found or the last equation and solve for and substitute for y or for z.\r<BR>\n" );
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document.write( "I'll try taking these two:<BR>\n" );
document.write( "5y-8z=10  AND  5y+z=10<BR>\n" );
document.write( "and solve the first one for y and substitute this into the next one:<BR>\n" );
document.write( "5y=10+8z<BR>\n" );
document.write( "y=2+8z/5<BR>\n" );
document.write( "Do the substitution into the other equation:<BR>\n" );
document.write( "5y+z=10<BR>\n" );
document.write( "5(2+8z/5)+z=10<BR>\n" );
document.write( "10+8z+z=10<BR>\n" );
document.write( "9z=0<BR>\n" );
document.write( "z=0.\r<BR>\n" );
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document.write( "Backsubstutite in any equation to find another variable.<BR>\n" );
document.write( "5y+0=10, the last of the given equations<BR>\n" );
document.write( "5y=10<BR>\n" );
document.write( "y=2.\r<BR>\n" );
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document.write( "Backsubstitute into any equation which has y; only one good one to choose; the first given equation.<BR>\n" );
document.write( "x-y=5<BR>\n" );
document.write( "x-2=5<BR>\n" );
document.write( "x=5+2<BR>\n" );
document.write( "x=7\r<BR>\n" );
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document.write( "SOLUTION:<BR>\n" );
document.write( "x=7, y=2, z=0.\r<BR>\n" );
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document.write( "After looking at the given system again, it seems like elimination might be easier for the system. </SPAN>\n" );
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