Complete the equation, and tell which property you used 11 + (19+6) = (11+) + 6

Properties:

1) a + b = b+a Commutative

2) (a + b) + c = a + (b+c) Associative

3) a (b+c) = ab + ac Distributive

Here we are given

11 + (19 + 6) = (11 + ___) + 6

The number 19 is missing on the right.

So we have

11 + (19 + 6) = (11 + 19) + 6

This looks like Property 2 above.

Hence it is associative property.