For the following system of equations, solve using Gaussian Elimination.
[ begin{bmatrix} 6 & -2 & 2 & 4 12 & -8 & 6 & 10 3 & -13 & 9 & 3 -6 & 4 & 1 & -18 end{bmatrix} begin{bmatrix} x₁ x₂ x₃ x₄ end{bmatrix} = begin{bmatrix} 16 26 -19 -34 end{bmatrix} ]