Which is

Commutative property

Associative property

3(4+5)=12+15

5+6+2=2+5+6

7+(3+4)=(7+3)+4

The commutative property is 3(4+5)=12+15, which means that the order of the numbers being added or multiplied does not affect the result.

The associative property is 5+6+2=2+5+6, which means that the grouping of numbers being added does not affect the result.

The equation 7+(3+4)=(7+3)+4 represents the associative property.