It's already in simplest form
Since the numbers 15 and 22 share no common positive integer factors other than 1, the proper fraction 15/22 is already expressed in its simplest form.15/22 is in its simplest form.
15/22
Assuming you meant 22/30 - its simplest form would be 11/15.
11/22 + 4/22 = 15/22 which is in its simplest form.
Its: 22/30 = 11/15
22/330 = 1/15
15/22
5/22
15/22
It is: 22/30 = 11/15 simplified
15/22
22/12 = 11/6 = 15/6