Chapter 3, Lesson 2


3-2.A understand the Commutative and Associative properties
Which of these expressions does not illustrate either a Commutative or an Associative Property?
(a)
1 + 9 = 9 + 1
(b) 1(9) = 9(1)
(c) 1(9) = 9
(d) 1 + (7 + 2) = (1 + 7) + 2

3-2.B understand the Distributive Property
Which of these expressions is equivalent to —5[8 — (—9)]?
(a)
—5(8) — (—9)
(b) —5(8) + 9
(c) —5(8) — 5(—9)
(d) —5(8) + 5(—9)