Which number properties is being used in the following math problem? 4(x+3)=4X+12

Question

What number properties are being used In the math problem

4(x+3)=4x+12

is it associative property of addition or

distributive property or 

associative property of multiplication or

communitive property of multiplication?

Answer 1

Distributive property.  This is because you are distributing the 4 to each term in parentheses.