Answer: 25.
- A 5
- B 10
- C 25
- D 125
Correct answer: C. 25
Explanation: det(adj A) = det(A)<sup>n−1</sup> = 5² = 25.
Element aij of matrix A sits at the intersection of row i and column j.
Concept context
Matrix operations, determinants, inverses, and solving linear systems