Nun, doch noch schön:
$$\left(\begin{array}{cc|cc} 3 & 1 & 1&0\\ 1 & 4 & 0&1 \end{array}\right)= \left(\begin{array}{cc|cc} 3 & 1 & 1&0\\ 0 & \frac{11}{3} & -\frac{1}{3}&1 \end{array}\right)= \left(\begin{array}{cc|cc} 3 & 0 & \frac{12}{11}&-\frac{3}{11}\\ 0 & \frac{11}{3} & -\frac{1}{3}&1 \end{array}\right)= \left(\begin{array}{cc|cc} 1 & 0 & \frac{4}{11}&-\frac{1}{11}\\ 0 & 1 & -\frac{1}{11}&\frac{3}{11} \end{array}\right)$$