In any calculation involving multiple operations, you have to know the correct order in which to do them. This is usually known as PEDMAS, BODMAS or similar.
I prefer to work with the concept of TERMS. Terms are separated by single PLUS or MINUS signs.
Each term is simplified separately to give a single answer and these are added or subtracted in the last step.
Within each term, the order is brackets, then indices, and then multiplication and division.
It is a good idea to write the ADD terms at the front and the SUBTRACT terms at the end.
This expression is already in this order.
You could also have noticed that: