# Thread: congruent

1. ## congruent

Given that xy' is congruent to x'y mod p, p is prime and that 0<xy', x'y<p then why can we say that xy'= x'y?

2. ## Re: congruent

"xy' congruent to x'y mod p" means that xy'- x'y is a multiple of p. if both xy' and x'y are positive and less than p, that "multiple" must be 0.