Answer
$x^{1/24}$
Work Step by Step
$\bf{\text{Solution Outline:}}$
Use the definition of rational exponents and the laws of exponents to simplify the given expression, $
\sqrt{\sqrt[3]{\sqrt[4]{x}}}
.$
$\bf{\text{Solution Details:}}$
Using the definition of rational exponents which is given by $a^{\frac{m}{n}}=\sqrt[n]{a^m}=\left(\sqrt[n]{a}\right)^m,$ the expression above is equivalent to
\begin{array}{l}\require{cancel}
\sqrt[2]{\sqrt[3]{x^{1/4}}}
\\\\=
\sqrt[2]{(x^{1/4})^{1/3}}
\\\\=
((x^{1/4})^{1/3})^{1/2}
.\end{array}
Using the Power Rule of the laws of exponents which is given by $\left( x^m \right)^p=x^{mp},$ the expression above is equivalent to
\begin{array}{l}\require{cancel}
x^{\frac{1}{4}\cdot\frac{1}{3}\cdot\frac{1}{2}}
\\\\=
x^{\frac{1}{24}}
\\\\=
x^{1/24}
.\end{array}