The Associative Property states that the way in which numbers are grouped in an addition or multiplication problem does not change the sum or product.
In the expression \(30m + (21m - 53) + (18 - 2m)\), you can regroup the terms without changing the overall value.
The expression:
\[ 30m + (21m - 53) + (18 - 2m) \]
can be rewritten using the associative property in this way:
\[ (30m + 21m) + (18 - 2m) - 53 \]
This form is represented in one of the responses:
\[ (30m + 21m) + (18 - 2m) - 53 \]
Thus, the equivalent expression using the Associative Property is:
(30m + 21m) + (18 - 2m)
Among the provided choices, that's exactly the fourth response:
(30m + 21m) + (18 - 2m)
This confirms the correctness using the associative property.