Which of the following is the simplified form of [tex]\sqrt{x} \cdot \sqrt[7]{x} \cdot \sqrt[7]{x}[/tex]?

A. [tex]x^{\frac{3}{7}}[/tex]
B. [tex]x^{\frac{1}{7}}[/tex]
C. [tex]x^{\frac{3}{21}}[/tex]
D. [tex]\sqrt[21]{x}[/tex]



Answer :

Let's simplify [tex]\(\sqrt{x} \cdot \sqrt[7]{x} \cdot \sqrt[7]{x}\)[/tex] step-by-step.

1. To start, we'll express each radical in terms of exponents:
- [tex]\(\sqrt{x} = x^{\frac{1}{2}}\)[/tex]
- [tex]\(\sqrt[7]{x} = x^{\frac{1}{7}}\)[/tex].

Therefore, the given expression [tex]\(\sqrt{x} \cdot \sqrt[7]{x} \cdot \sqrt[7]{x}\)[/tex] can be written as:
[tex]\[ x^{\frac{1}{2}} \cdot x^{\frac{1}{7}} \cdot x^{\frac{1}{7}} \][/tex]

2. When multiplying expressions with the same base, we add their exponents:
[tex]\[ x^{\frac{1}{2}} \cdot x^{\frac{1}{7}} \cdot x^{\frac{1}{7}} = x^{\left(\frac{1}{2} + \frac{1}{7} + \frac{1}{7}\right)} \][/tex]

3. Now, let's add the exponents. Sum up the fractions:
[tex]\[ \frac{1}{2} + \frac{1}{7} + \frac{1}{7} \][/tex]

First, find a common denominator. The common denominator for 2 and 7 is 14:
[tex]\[ \frac{1}{2} = \frac{7}{14} \][/tex]
[tex]\[ \frac{1}{7} = \frac{2}{14} \][/tex]

Adding these fractions together:
[tex]\[ \frac{7}{14} + \frac{2}{14} + \frac{2}{14} = \frac{7 + 2 + 2}{14} = \frac{11}{14} \][/tex]

4. Therefore, the exponent simplifies to [tex]\(\frac{11}{14}\)[/tex]:
[tex]\[ x^{\frac{1}{2} + \frac{1}{7} + \frac{1}{7}} = x^{\frac{11}{14}} \][/tex]

Thus, the simplified form of [tex]\(\sqrt{x} \cdot \sqrt[7]{x} \cdot \sqrt[7]{x}\)[/tex] is [tex]\(x^{\frac{11}{14}}\)[/tex].

Among the options given:
- [tex]\(x^{\frac{3}{7}}\)[/tex]
- [tex]\(x^{\frac{1}{7}}\)[/tex]
- [tex]\(x^{\frac{3}{21}}\)[/tex]
- [tex]\(\sqrt[21]{x}\)[/tex]

None of the provided options match our result. Therefore, based on the available choices, none of these is the correct simplified form for [tex]\(\sqrt{x} \cdot \sqrt[7]{x} \cdot \sqrt[7]{x}\)[/tex]. The correct simplified form not listed among the options would be [tex]\(x^{\frac{11}{14}}\)[/tex].