The cofactor of an element, aij, is its minor prefixing:
+ sign if i+j is even.
− sign if i+j is odd.
The value of a determinant is equal to the sum of the products of the elements of a line multiplied by its corresponding cofactors:
= 3(8+5) - 2(0-10) + 1(0+4) = 39 + 20 + 4 = 63