Which property of real numbers is illustrated in each part of Problems 1 and 2?
1. (a) 8 + 6 = 6 + 8
(b) 5(3 + 7) = 5(3) + 5(7)
(c) 6(4 ( 5) = (6 ( 4)(5)
(d) -15 + 0 = -15
2. (a) -e ( 1 = -e
(b) 4 + (-4) = 0
(c) (3/2) (2/3) = 1
(d) (12) (3/4) = (3/4) (12)