Hello all! Are somewhere existed a method for solving a linear equations over matrices? For example, I have a task that is similar to next: find $l \times l$ - matrix $A \in M_{l \times l}(\mathbf{F}_q)$ over $\mathbf{F}_q$ that vanishes $B_0 + B_1 X + B_2 X^2 + B_3 x^3 + ... + B_m X^m$ where $B_i \in M_{l \times l}(\mathbf{F}_q)$. I have found nothing about this by Google. Thank you!