Answer:
the Associative Property
Explanation:
Notice that the ORDER doesn't change -- a, b, c on both sides. But the GROUPING changes.
Example:
3 + (4 + 5) = (3 + 4) + 5
3 + 9 = 7 + 5
12 = 12
Subtraction does NOT behave this way!
8 - (7 - 1) = 8 - 6 = 2
(8 - 7) - 1 = 1 - 1 = 0
It matters who you associate with! :-)