Determine whether the following relation is an equivalence relation:

1. For all x,y element of Real # xRy <-> x-y is an integer.

2. For all a,b elemnt of Natural # aRb <-> a ends in the same digit in which be ends

With equivalence relation, i am so lost. I could really use some help here please. This section of the book is just not making much sense to me. Thank you