## Algebra 1

We start with the first expression: $(6+b)+a$ The associative property of addition states that changing the grouping of the addends does not affect the sum. We use this property to change the grouping of the addends: $6+(b+a)$ The commutative property of addition states that changing the order of the addends does not affect the sum. We use this property to change the order of the addends: $6+(a+b)$ Since this expression is the same as the second expression, the expressions are equivalent.