Name the property demonstrated by the following equation: (5 + 4) + 6 = 5 + (4 + 6).
a. associative property of addition
b. associative property of multiplication
c. commutative property of addition
d. commutative property of multiplication

The associative property states that you can add or multiply and get the same answer, despite how the numbers are grouped (or where you place the parenthesis).

So, I would go with A. Associative Property of Addition. B makes no sense since there is no multiplication used here. 

I hope this is helpful! :D

The answer is 41.7 because 1.39 times 30 is 41.7