ABSTRACT
This chapter focuses on linear congruences; i.e., congruences of the form ax=b(modn), where a and b are fixed integers, n is a fixed integer greater than 1, and x is an unknown integer. In fact, we shall seek solutions x which lie in Zn, so the set of possible solutions is finite to start with. We shall see that in this set a given linear congruence may have no solutions, a unique solution, or multiple solutions. We now turn to the matter of attempting to solve congruences which contain an unknown.
