How many distinct equivalence classes are there?

Figure out what else it has to have, and then we can talk. a=a, since anything is equal to itself (i.e., by reflexivity). So the set of elements equal to (related to) a, namely the equivalence class of a is {a,b,c,d,e}. In other words, in this case there is just one equivalence class, everything.

What the heck don’t understand