Textbook Problem

As in Example 8.1.2, the congruence modulo 2 relation E is defined from Z to Z as follows: For every ordered $\left(m,n\right)\in Z\times Z.$

$mEn\iff m-n\text{is}\text{even}\text{.}$

1. Is 0 E 0? Is 5 E 2? Is (6,6) $\in E$?
2. Prove that for any even integer $n,nE0$ .