Which of the following is the rational exponent expression of [tex]\sqrt[5]{7n}[/tex]?

A. [tex]5 n^7[/tex]

B. [tex](7 n)^5[/tex]

C. [tex]7 n^{\frac{1}{5}}[/tex]

D. [tex](7 n)^{\frac{1}{5}}[/tex]



Answer :

To determine the rational exponent expression of the given expression [tex]$\sqrt[5]{7n}$[/tex], we can follow a clear step-by-step method.

1. Understand the Problem:
We need to convert the fifth root of [tex]\( 7n \)[/tex] into an expression with rational exponents.

2. Recall the Rule for Converting Roots to Rational Exponents:
The [tex]\( n \)[/tex]-th root of a number [tex]\( a \)[/tex] is expressed with rational exponents as:
[tex]\[ \sqrt[n]{a} = a^{\frac{1}{n}} \][/tex]

3. Apply the Rule:
- Here, we have the fifth root of [tex]\( 7n \)[/tex].
- According to the rule, this can be written as:
[tex]\[ \sqrt[5]{7n} = (7n)^{\frac{1}{5}} \][/tex]

4. Check the Options Given:
- Option 1: [tex]\( 5 n^7 \)[/tex] — This is [tex]\( 5 \times n^7 \)[/tex], not related to our expression.
- Option 2: [tex]\( (7 n)^5 \)[/tex] — This represents [tex]\( 7n \)[/tex] raised to the power of 5, not [tex]\((7n)^{\frac{1}{5}}\)[/tex].
- Option 3: [tex]\( 7 n^{\frac{1}{5}} \)[/tex] — This means [tex]\( 7 \times n^{\frac{1}{5}} \)[/tex], which only raises [tex]\( n \)[/tex] to the power [tex]\( \frac{1}{5} \)[/tex].
- Option 4: [tex]\( (7 n)^{\frac{1}{5}} \)[/tex] — This correctly represents the entire expression [tex]\( 7n \)[/tex] raised to the power [tex]\( \frac{1}{5} \)[/tex].

5. Select the Correct Option:
Among the given options, the correct representation of [tex]\( \sqrt[5]{7n} \)[/tex] using rational exponents is:
[tex]\[ (7 n)^{\frac{1}{5}} \][/tex]

Therefore, the correct answer is:
[tex]\[ \boxed{(7 n)^{\frac{1}{5}}} \][/tex]