The ≡ indicates "equivalence." Therefore 3 and 7 are equivalent modulo 4 because both of them leave a remainder of 3 upon dividing by 4.
I am confused about modular arithmetic, even the basis of it.
When it says that 3 ≡ 3 (mod 4), does that mean that 3 : 4 has a reminder of 3? Because 4 x 0 + 3 = 3?
When it says that 3 ≡ 7 (mod 4), does that mean that 3 : 4 also kind of has a reminder of 7? How would that work?
I am so sorry, I know these are trivial questions, I hope I am not wasting your time, I read through this chapter in my book two times now and I always get stuck at the basics.
Thanks to anyone who reads this!