prove that if $n>0$ is a positive integer then relation $\equiv_n$ on integers defined by $a\equiv_n b$ if $n\mid (a − b)$ is an equivalence relation. what if $n=2$?
so i know we have to proof reflexivity, symmetry and transitivity.
$\tag 1 a\sim a ?$ $\tag 2 a\sim b \text{ then } b\sim a$ $\tag 3 a\sim b, b\sim c \text{ then } a=c$
but im kind of confused of how to prove it