Question 638518
x-2y+3z=9
y+3z=5
z=2 


is the same as


1x-2y+3z=9
0x+1y+3z=5
0x+0y+1z=2 


which converts to the following augmented matrix


<img src="http://latex.codecogs.com/gif.latex?\left[ \begin{array}{ccc|c} 1 & -2 & 3 & 9 \\ 0 & 1 & 3 & 5 \\ 0 & 0 & 1 & 2 \\ \end{array} \right]" title="\left[ \begin{array}{ccc|c} 1 & -2 & 3 & 9 \\ 0 & 1 & 3 & 5 \\ 0 & 0 & 1 & 2 \\ \end{array} \right]" />