∣100021212∣=4−1=3\begin{vmatrix} 1 & 0 & 0 \\ 0 & 2 & 1 \\ 2 & 1 & 2 \end{vmatrix} = 4 - 1 = 3102021012=4−1=3 ∣2112∣=4−1=3−∣0012∣=0−∣0021∣=0\begin{vmatrix} 2 & 1 \\ 1 & 2 \end{vmatrix} = 4 - 1 = 3 \quad - \begin{vmatrix} 0 & 0 \\ 1 & 2 \end{vmatrix} = 0 \quad - \begin{vmatrix} 0 & 0 \\ 2 & 1 \end{vmatrix} = 02112=4−1=3−0102=0−0201=0 −∣0122∣=2∣1022∣=2−∣1001∣=−1- \begin{vmatrix} 0 & 1 \\ 2 & 2 \end{vmatrix} = 2 \quad \begin{vmatrix} 1 & 0 \\ 2 & 2 \end{vmatrix} = 2 \quad - \begin{vmatrix} 1 & 0 \\ 0 & 1 \end{vmatrix} = -1−0212=21202=2−1001=−1 ∣0221∣=−4−∣1021∣=−1∣1002∣=2\begin{vmatrix} 0 & 2 \\ 2 & 1 \end{vmatrix} = -4 \quad - \begin{vmatrix} 1 & 0 \\ 2 & 1 \end{vmatrix} = -1 \quad \begin{vmatrix} 1 & 0 \\ 0 & 2 \end{vmatrix} = 20221=−4−1201=−11002=2 これから 13(30022−1−4−12)\frac{1}{3}\begin{pmatrix} 3 & 0 & 0 \\ 2 & 2 & -1 \\ -4 & -1 & 2 \end{pmatrix}3132−402−10−12