​Write the System of Linear Equations as a Matrix Equation

Essay

​Write the system of linear equations as a matrix equation AX = B,and use Gauss-Jordan elimination on the augmented matrix [A|B] to solve for the matrix X.Show all your work.​ $$\left\{ \begin{array} { r l r } x _ { 1 } + 8 x _ { 2 } - 3 x _ { 3 } & = 66 \\- x _ { 1 } - 9 x _ { 2 } + 8 x _ { 3 } & = - 101 \\9 x _ { 1 } + 9 x _ { 2 } + 3 x _ { 3 } & = 99\end{array} \right.$$