What type of property is > 7.2 x (1.6 x 3.9) = (7.2 x 1.6) x 3.9

What are the values of a, b, and c in the quadratic equation 0 = x2 – 3x - 2? a = 1, b = 3, c = 2 a=, b = -3,c=-2 a = 1, b = 3, c= 2 a = 1.0= -3, c = 2