57. For what positive real value of k, if any, is the determinant of the matrix equal to k?

(Note: The determinant of matrix equals ad - bc. )

Answer and Explanation

Your Answer is

Correct Answer is B

Explanation

According to the note, the determinant of the matrix is ​​k2 - 12,

k2 - 12 = k

(k-4)(k+3) = 0

k1 = 4, k2 = -3

Option B fits.