What equation shows an example of the associative property of addition

Addition has three properties. These properties are commutative property of addition, associative property of addition, and identity property of addition.

Associative property of addition is the property where the grouping of addends can be changed resulting to the same sum.

(a + b) + c = a + (b +c)

Example: a = 1; b = 2; c = 3

1 + 2 + 3 = 6

(1 + 2) + 3 = 1 + (2 + 3)
3 + 3 = 1 + 5
6 = 6

These are the multiples of 15 but what you are probably asking or what are the factors of 15