Factorise: `27 x^3+y^3+z^3-9x y z`

Explanation

To factorize the expression \( 27x^3 + y^3 + z^3 - 9xyz \), we can use the identity for the sum of cubes and the product of three variables. The identity states:

\[ A^3 + B^3 + C^3 - 3ABC = (A + B + C)(A^2 + B^2 + C^2 - AB - BC - CA) \]

### Step 1: Identify A, B, and C
In our case, we can rewrite the expression as follows:
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