Review Practice Activity

In the following practice activity, you will determine how the properties of equality are used. This practice is aligned with Lesson 5.

1. Which of the following properties could be used to rewrite the expression [tex]\left(\frac{1}{3} \cdot \frac{2}{3}\right) \cdot \frac{5}{2}=\frac{2}{3} \cdot\left(\frac{1}{3} \cdot \frac{5}{2}\right)[/tex]?

A. The commutative property followed by the associative property
B. The associative property used once
C. The associative property followed by the commutative property
D. The commutative property used twice, once on each of the two multiplications

2. Rewrite [tex]35 \cdot y[/tex] in a different way, using the commutative property of multiplication. Note that [tex]y[/tex] represents [tex]a[/tex].



Answer :

Let's answer the given question step-by-step.

We start with the original expression:
[tex]\[ \left(\frac{1}{3} \cdot \frac{2}{3}\right) \cdot \frac{5}{2} = \frac{2}{3} \cdot\left(\frac{1}{3} \cdot \frac{5}{2}\right) \][/tex]

The properties of multiplication we need to consider are:
1. The commutative property of multiplication, which states that [tex]\(a \cdot b = b \cdot a\)[/tex].
2. The associative property of multiplication, which states that [tex]\((a \cdot b) \cdot c = a \cdot (b \cdot c)\)[/tex].

Let's examine the transformation of the left-hand side (LHS) of the expression to the right-hand side (RHS).

- Initially, on the LHS, the expression is grouped as [tex]\(\left(\frac{1}{3} \cdot \frac{2}{3}\right) \cdot \frac{5}{2}\)[/tex].

- On the RHS, the expression is grouped as [tex]\(\frac{2}{3} \cdot \left(\frac{1}{3} \cdot \frac{5}{2}\right)\)[/tex].

To transform LHS to RHS:
- We see that we need to regroup the factors in the multiplication.
- This regrouping uses the associative property of multiplication. Applying the associative property, we change the grouping while maintaining the order of multiplication.

Thus, the correct and specific property being used in this transformation is the associative property used once.

So, the answer is:
[tex]\[ \textbf{The associative property used once.} \][/tex]

Next, we are asked to rewrite [tex]\(35 \cdot y\)[/tex] in a different way using the commutative property of multiplication. According to the commutative property:
[tex]\[ 35 \cdot y = y \cdot 35 \][/tex]

Hence, using the commutative property, [tex]\(35 \cdot y\)[/tex] can be rewritten as [tex]\(y \cdot 35\)[/tex].