15(93−67)\frac{1}{5}\left(\begin{array}{rr}9 & 3 \\-6 & 7\end{array}\right)51(9−637)
(93−67)\left(\begin{array}{rr}9 & 3 \\-6 & 7\end{array}\right)(9−637)
(1001)\left(\begin{array}{ll}1 & 0 \\0 & 1\end{array}\right)(1001)
(−3−7−2−5)\left(\begin{array}{ll}-3 & -7 \\-2 & -5\end{array}\right)(−3−2−7−5)