13 is already prime. 13/14 is in simplest form already.
13/16 is the simplest form.
It already is in simplest form: 13/100
13/57. It is already in the simplest form.
13/30 is already in its simplest form
13/31 is already in its simplest form
44/13 is already in its simplest form
13/50 is already in its simplest form.
It is already in its simplest form.
It is already in simplest form!
13/5 is already in simplest form.
It's already in its simplest form of 13/64