I'm assuming that the matrix is a 2 x 2 matrix.
| -2 5 |
| 4 3 |
To determine the determinant of the matrix, we simply find the difference of the product of its diagonals.
| a b |
| c d | → ad - bc = determinant
| -2 5 |
| 4 3 | → [(-2) * 3] - (5*4) = -6 - 20 = -26
Even though the determinants are place in an absolute-value bars, they can still be negative form.
The determinant in the above matrix is -26.