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# Determinants

The symbol $A=\left|\begin{matrix}a_{11}&a_{12}&a_{13}\\a_{21}&a_{22}&a_{23}\\a_{31}&a_{32}&a_{33}nd{matrix}\right|$ is a determinant of third order that consists of nine numbers arranged in three rows and three columns.
By definition, the value of a determinant of third order is given by:

|A| = a11a22a33+a13a21a32+a12a23a31-a13a22a31-a12a21a33-a11a23a33

and is called the expansion of the determinant.

To remember easily, you can use:

Express the value of the determinant:
 2 -1 -8 -1 -2 3 -1 -3 2
Solution: