Which expression is equivalent to [tex]$81^{\frac{1}{3}}$[/tex]?

A. [tex]3 \sqrt[3]{3}[/tex]

B. [tex]3 \sqrt{3^3}[/tex]

C. [tex]9 \sqrt[3]{3}[/tex]

D. [tex]27 \sqrt[3]{3}[/tex]



Answer :

To determine which expression is equivalent to [tex]\( 81^{\frac{1}{3}} \)[/tex], we need to evaluate each given option and compare it to the original expression:

1. Option 1: [tex]\( 3 \sqrt[3]{3} \)[/tex]

Let's simplify this expression:
[tex]\[ 3 \sqrt[3]{3} = 3 \cdot 3^{\frac{1}{3}} \][/tex]

2. Option 2: [tex]\( 3 \sqrt{3^3} \)[/tex]

Simplify the inner part first:
[tex]\[ \sqrt{3^3} = \sqrt{27} \][/tex]
And then multiply by 3:
[tex]\[ 3 \sqrt{27} \][/tex]

3. Option 3: [tex]\( 9 \sqrt[3]{3} \)[/tex]

Let's simplify this expression:
[tex]\[ 9 \sqrt[3]{3} = 9 \cdot 3^{\frac{1}{3}} \][/tex]

4. Option 4: [tex]\( 27 \sqrt[3]{3} \)[/tex]

Let's simplify this expression:
[tex]\[ 27 \sqrt[3]{3} = 27 \cdot 3^{\frac{1}{3}} \][/tex]

Now, we need to compare these values to [tex]\( 81^{\frac{1}{3}} \)[/tex].

Evaluate the original expression:

[tex]\[ 81^{\frac{1}{3}} = (3^4)^{\frac{1}{3}} = 3^{\frac{4}{3}} = 3^{1 + \frac{1}{3}} = 3 \cdot 3^{\frac{1}{3}} \][/tex]

From our simplified evaluations, we see that:

[tex]\[ 81^{\frac{1}{3}} = 3 \cdot 3^{\frac{1}{3}} \][/tex]

This matches exactly with Option 1:

[tex]\[ 3 \sqrt[3]{3} \][/tex]

Therefore, the expression equivalent to [tex]\( 81^{\frac{1}{3}} \)[/tex] is [tex]\( 3 \sqrt[3]{3} \)[/tex].