Question: Two Examples (NOT from class!)
10. Use #1-9 to identify each property below.
A. $ab^2 \cdot 0 = 0$
B. $(7 + 5) + 1 = 7 + (5 + 1)$
C. $6 = 6$
D. $7(x - 3) = 7x - 21$
E. $x + (-x) = 0$
F. if $y = 3$, then $3 = y$
G. $(a + b) + 0 = 0 + (a + b)$
H. if $x = -1$, and $-1 = z$, then $x = z$
I. $4x \cdot 1 = 4x$
1. **State the problem:** Identify the property illustrated by each equation or statement using properties numbered #1-9.
2. **Recall common algebraic properties:**
- #1: Multiplicative Property of Zero: $a \cdot 0 = 0$
- #2: Associative Property of Addition: $(a + b) + c = a + (b + c)$
- #3: Reflexive Property of Equality: $a = a$
- #4: Distributive Property: $a(b + c) = ab + ac$
- #5: Additive Inverse Property: $a + (-a) = 0$
- #6: Symmetric Property of Equality: If $a = b$, then $b = a$
- #7: Additive Identity Property: $a + 0 = a$
- #8: Transitive Property of Equality: If $a = b$ and $b = c$, then $a = c$
- #9: Multiplicative Identity Property: $a \cdot 1 = a$
3. **Identify each property:**
A. $ab^2 \cdot 0 = 0$ uses #1 Multiplicative Property of Zero.
B. $(7 + 5) + 1 = 7 + (5 + 1)$ uses #2 Associative Property of Addition.
C. $6 = 6$ uses #3 Reflexive Property of Equality.
D. $7(x - 3) = 7x - 21$ uses #4 Distributive Property.
E. $x + (-x) = 0$ uses #5 Additive Inverse Property.
F. if $y = 3$, then $3 = y$ uses #6 Symmetric Property of Equality.
G. $(a + b) + 0 = 0 + (a + b)$ shows both sides equal but more closely matches #7 Additive Identity Property (though written symmetrically).
H. if $x = -1$, and $-1 = z$, then $x = z$ uses #8 Transitive Property of Equality.
I. $4x \cdot 1 = 4x$ uses #9 Multiplicative Identity Property.
4. **Summary:**
- A: #1
- B: #2
- C: #3
- D: #4
- E: #5
- F: #6
- G: #7
- H: #8
- I: #9
This completes the identification of each property.