[2−10−3]\left[\begin{array}{rr}2 & -1 \\0 &-3\end{array}\right][20−1−3]
[−2−140]\left[\begin{array}{rr}-2 & -1 \\4 & 0\end{array}\right][−24−10]
[−2−4−3−3]\left[\begin{array}{rr}-2 & -4 \\-3 & -3\end{array}\right][−2−3−4−3]
[2−100]\left[\begin{array}{cc}2 & -1 \\0 & 0\end{array}\right][20−10]
