$\"\"$

Observe the matrix; the matrix has 2 rows and 2 columns.

So, the dimensions of matrix are $\"\"$ .

The determinant of a $\"\"$ matrix is called a second-order determinant.

Second-order determinant definition is: $\"\"$ $\"\"$

Find the determinant using second-order determinant definition.

Slove for x if det $\"\"$

$\"\"$

Add 6 to each side. \ \

$\"\"$

Divide each side by negative 5.

$\"\"$

$\"\"$ $\"\"$

The value of $\"\"$ .