Yes.
1/3 is the simplest form.1/3 is the simplest form.1/3 is the simplest form.1/3 is the simplest form.
x - 1 is in its simplest form.
11/21
1/4 is in its simplest form.
1/18 is in its simplest form.
1 and 1/3 is in its simplest form.
1/12 is in its simplest form.1/12 is in its simplest form.
1/7 is in its simplest form.
1/2 is in its simplest form.
1/5 is in its simplest form.
1/12 is in its simplest form.
1/4 is in its simplest form: it cannot be reduced further.