Answer is (B) (C)
It is given that
Solving Eqs. (1) and (2), we get
−4 = −k ⇒ k = 4
Using the value of k in Eq. (1), we get
6α + 10 = 4 ⇒ α = −1
That is, α = −1 and k = 4.
Hence, option (A) is incorrect.
The values of α = −1 and k = 4 satisfy the equation given in option (B).
Hence, option (B) is correct.
Now, det Q = k2/2 = 8
Therefore, det(P adj Q) = (det P)det(adj Q) = (2 × 4)(detQ)2
= 8 × 82 = 23 × 26 = 29