The given system of linear equations can be written as shown below:

\(x-y+z=8\)

\(0x+y-12z=-15\)

\(0x+0y+z=1\)

Thus the augmented matrix could be written as

\(\displaystyle{\left[\begin{matrix}{1}&-{1}&{1}&{|}&{8}\\{0}&{1}&-{12}&{|}&-{15}\\{0}&{0}&{1}&{|}&{1}\end{matrix}\right]}\)