12/23 is already in simplest form.
1x23 is the only way to get 23 so 12/23 is the simplest form.
23/21 = 12/21
12/23
23/6
12/23
12/46 = 6/23
23/53 is in its simplest form.
As 23 is prime, that is the simplest form.
23/48 is in its simplest form.
23/50 is the simplest form.
1/23 is the simplest form.
23/75 is in its simplest form.