document.write( "Question 358649: x+y+3z=-4
\n" ); document.write( "2x -z=-3
\n" ); document.write( "-x-y-2z=5 \n" ); document.write( "
Algebra.Com's Answer #255986 by Edwin McCravy(20059)\"\" \"About 
You can put this solution on YOUR website!
\r\n" );
document.write( " x + y + 3z = -4\r\n" );
document.write( "2x     -  z = -3\r\n" );
document.write( "-x - y - 2z =  5\r\n" );
document.write( "\r\n" );
document.write( "Since y is already eliminated from the second equation,\r\n" );
document.write( "eliminate y from the 1st and 2nd equations.  We only need\r\n" );
document.write( "to add them term by term: \r\n" );
document.write( "\r\n" );
document.write( " x + y + 3z = -4\r\n" );
document.write( "-x - y - 2z =  5\r\n" );
document.write( "----------------\r\n" );
document.write( "          z =  1\r\n" );
document.write( "\r\n" );
document.write( "Next we sustitute in the 2nd original equation:\r\n" );
document.write( "\r\n" );
document.write( "     2x - z = -3\r\n" );
document.write( "     2x - 1 = -3\r\n" );
document.write( "         2x = -2\r\n" );
document.write( "          x = -1\r\n" );
document.write( "\r\n" );
document.write( "Finally substitute in the 1st original equation:\r\n" );
document.write( "\r\n" );
document.write( "   x + y + 3z = -4\r\n" );
document.write( "-1 + y + 3(1) = -4\r\n" );
document.write( "  -1 + y + 3 = -4\r\n" );
document.write( "       2 + y = -4\r\n" );
document.write( "           y = -6\r\n" );
document.write( "\r\n" );
document.write( "Solution is (x,y,z) = (-1,-6, 1)\r\n" );
document.write( "\r\n" );
document.write( "Edwin
\n" ); document.write( "
\n" );