TeX джерело:

A_{12}\,=\,-\,\left|\begin{array}{rr}3&2\\2&4\end{array}\right|=-8,\;\; A_{22}\,=\,-\,\left|\begin{array}{rr}1&1\\2&4\end{array}\right|=2,\;\; A_{32}\,=\,-\,\left|\begin{array}{rr}1&1\\3&2\end{array}\right|=1,\;\;