Maybe this is obvious but I'm completely at a loss here. How do i write
$B = \begin{bmatrix} \mathbf{k}A_{11} & \mathbf{k}A_{12} \\ \mathbf{k}A_{21} & \mathbf{k}A_{22} \end{bmatrix}$
As a product of matrices/vectors where both $\mathbf{k}$ and $\mathbf{A_{ij}}$ is vectors.