The property being used below is the Associative Property?
7 + (a + b) = (7 + a) + b
Yes, the property being used in the equation you provided is the Associative Property of Addition.
The Associative Property states that the grouping of numbers being added does not affect the sum. In other words, you can regroup the numbers being added in any way and still get the same result.
In the given equation, you have three numbers being added: 7, a, and b. The expression on the left side of the equation has the grouping of (a + b), meaning that a and b are added together first. The expression on the right side of the equation has the grouping of (7 + a), meaning that 7 and a are added together first. However, since addition is associative, it doesn't matter which grouping you choose. The result will be the same.
So, the equation 7 + (a + b) = (7 + a) + b demonstrates the use of the Associative Property of Addition.