Determine which property is illustrated by the given equation. 3+(1+7)=(3+1)+7

The given equation is demonstrating the Associative Property of Addition. This property states that the way in which numbers are grouped does not change their sum. In other words, the sum remains the same even when the grouping of the addends is altered. In the given equation, whether we group 1 and 7 together first (as in 3+(1+7)), or 3 and 1 together first (as in (3+1)+7), the sum is the same (11). Therefore, the equation is illustrating the Associative Property of Addition.