The associative property of addition states that when adding three or more numbers, the way in which the numbers are grouped does not change the sum. In the case of the expression \(3x + 2y + z\), we can apply the associative property by grouping the terms in different ways.
For example: \[ (3x + 2y) + z \] or \[ 3x + (2y + z) \]
Both of these groupings reflect the associative property, as they indicate that the addition can be performed in any order without changing the final result.