(−2321−12)\left(\begin{array}{rr}-2 & \frac{3}{2} \\1 & -\frac{1}{2}\end{array}\right)(−2123−21)
(2−3−11)\left(\begin{array}{cr}2 & -3 \\-1 & 1\end{array}\right)(2−1−31)
12(4−3−21)\frac{1}{2}\left(\begin{array}{rr}4 & -3 \\-2 & 1\end{array}\right)21(4−2−31)
−12(4321)-\frac{1}{2}\left(\begin{array}{ll}4 & 3 \\2 & 1\end{array}\right)−21(4231)