How Do Compatible Observable Properties Transform Between Equations?

[alui]

Homework Statement

I have problem with properties of compatible observable

Homework Equations

[AB,CD]=AB CD – CD AB ………. (1)
ABCD+ACBD-ACBD-ACDB+ACDB+CADB-CADB-CDAB ………. (2)
A{C,B}D-AC{D,B}+{C,A}DB-C{D,A}B ... (3)

The Attempt at a Solution

How can the equation (1) become (2), and eq (2) become (3), someone please explain to me about that properties

 

[mfb]

Try to check the other direction: verify that (3) is equal to (2) and then see if you can simplify (2) to (1).
There is no magic going on.