Given $4 \times 2$ matrix $V$ and $4 \times 1$ matrix $K$, solve the linear system $V A = K$ for $A$.
If V was a square matrix I could just multiply by the inverse, but I cannot since it is not. Apparently, the solution is of the form
$$A=(V'*V)\(V' K)$$
where $V'$ is the transpose of $V$.
What is this called? The algebra seems to be out of nowhere. I know that the transpose of $V$ theoretically is cancelled out, but it seems like dividing which is not allowed in matrix algebra.