This is a problem of  classical cryptography: Hill-Chiffre Where the matrix $A$ is the clear message and the matrix $C$ the coded message.How can I find the Matrix $X$?Which method I can use?$$\underbrace{\begin{pmatrix} 15 &4 & 17 \\12 &20 & 19\\0 &19 &8\\14 &13 &18\\10 &17 &24\\15 &19 &14\\18 &24 &18\\19 &4 &12\\\end{pmatrix}}_{A} \cdotX = B\pmod{26} =\underbrace{\begin{pmatrix}8 &3 &0\\18 &1 &23\\19 &13 &7\\15 &5 &13\\11 &23 &17\\23 &19 &0\\8 &12 &2\\16 &24 &5\end{pmatrix} }_{C}$$Thanks in advance.
Hill-Chiffre - How can I find the Matrix $X$
cryptography;linear algebra;modular arithmetic