(−7−1−13)\left(\begin{array}{rr}-7 & -1 \\-1 & 3\end{array}\right)(−7−1−13)
(−45−40)\left(\begin{array}{ll}-4 & 5 \\-4 & 0\end{array}\right)(−4−450)
(−4540)\left(\begin{array}{rr}-4 & 5 \\4 & 0\end{array}\right)(−4450)
(4546)\left(\begin{array}{ll}4 & 5 \\4 & 6\end{array}\right)(4456)