Final answer:
The equation is an example of the associative property of addition, as it demonstrates that the grouping of numbers in addition does not change the sum. The Associative property states that the way numbers are grouped in an addition expression does not affect the sum. In this equation, both sides have the same sum of 23, regardless of how the numbers are grouped.
Step-by-step explanation:
The equation (5 + 7) + 11 = 5 + (7 + 11) illustrates the associative property of addition. This property states that the grouping of numbers being added does not affect the sum. Therefore, regardless of how the numbers are grouped or associated (with parentheses), the result of the addition remains the same.