Question 92959
The following matrix is obtained from a system of equations 
{{{(matrix(3,4, 1, 0, 6, 5, 0, 1, -4, 3,0, 0,  2, -6)) }}} 

The solution to the system is ___________.
<pre><font face = "lucida console" size = 5 color = "darkblue"><b>
This matrix is an abbreviation for

1x + 0x + 6z =  5
0x + 1y - 4z =  3
0x + 0y + 2z = -6

or, after erasing the 0 terms and the 
1 coefficients:

 x      + 6z =  5
      y - 4z =  3
          2z = -6

Solve the bottom equation for z

          2z = -6
           z = -3

Substitute that in the middle equation:

      y - 4z =  3
   y - 4(-3) =  3
      y + 12 =  3
           y = -9

Substitute z = -3 in the top equation:

 x      + 6z =  5
      x + 6z = 5
   x + 6(-3) = 5
      x - 18 = 5
           x = 23

So the solution is

(x, y, z) = (23, -9, -3)

Edwin</pre>