Name the property of real numbers -3x(x+4)=-3x-12

-Distributive Property
-Associative Property of Addition
-Associative Property of Multiplication
-Commutative Property of Addition

Astudent draws two parabolas both parabolas cross the x axis at (-4,0) and (6,0) the y intercept of the first parabolas is (0,-12). the y intercept of the second parabola is (0,-24) what is the positive difference between the a values for the two functions that describe the parabolas