If P and Q are symmetric matrices, then QP-PQ is

If A is a square matrix of order 3 such that $|A| = 3$, then $|adj(adj A)|$ is equal to:

If A and B are invertible matrices of order 3, $|A| = 2$ and $|(AB)^{-1}| = -\frac{1}{6}$, then the value of $|B|$ is :

For what values of $\lambda$ and $\mu$, the following system of linear equations:

$x+y+2z=1, 2x+y-z=4, x+2y+\lambda z=\mu$

have infinitely many solution?

Let $A = \begin{bmatrix} 3 & -1 \\ 2 & 4 \end{bmatrix}$, then adjoint (A) is:

If $\begin{vmatrix}6 & 7\\ 3 & 8\end{vmatrix} = \begin{vmatrix}3x & 6\\ -1 & x\end{vmatrix}$, then the sum of values of $x$ is equal

If the area of a triangle whose vertices are $(-2, 4)$, $(2, -6)$ and $(k, 4)$, $(k > 0)$ is 35 squnits, then the value of k is