Let A = {1,2,4,5,6,8,11,13,15,17,153}. Define a relation R on A by writing (x,y) R iff x - y is a multiple of 5.

a) Show that R is an equivalence on A.

My answer:

Is it reflexive? Yes, since x-x = ,

Is it symmetric? No, since but ,

Is this reflexive and symmetric ones correct? thanks