TeX джерело:
{\;\;\left|\begin{array}{ccc}\bf a_{11}&\bf a_{12}&\bf a_{13}\\a_{21}&a_{22}&a_{23}\\ a_{31}&a_{32}&a_{33} \end{array}\right|=\;-\;\left|\begin{array}{ccc}a_{21}&a_{22}&a_{23}\\\bf a_{11}&\bf a_{12}&\bf a_{13}\\ a_{31}&a_{32}&a_{33} \end{array}\right|}