The matrix is:
$$\begin{pmatrix} 3+l & 8 & 3 & 3+l \\ 8 & 9 & 3 & 7 \\ 3 & 3 & 7 & 8 \\ 3+l & 7 & 8 & 13 \end{pmatrix}$$
I'm given the above matrix, and I'm asked to figure if it can be the matrix of a linear transformation, for a given $l$.
What is the methodology to find a linear transformation that uses the above as its matrix?