How to solve linear equations using modulo?

Question

In one of my projects, I came across a set of linear equations. with the module. I put it in a simple format with two variables,

(a11x + a12y) mod 8 = b1
(a21x + a22y) mod 8 = b2

In the case of simple equations. with the module I can use: AX = B, X = inv (A) * B. But how to deal with this module? Any hints or pointers will be very helpful.