recall that something inside a radical, comes out only if it's raised to the same root as the radical, for examples,
[tex]\bf \sqrt{25}\implies \sqrt{5^2}\implies \sqrt[2]{5^2}\implies 5
\\\\\\
\sqrt{27}\implies \sqrt{3^3}\implies \sqrt[3]{3^3}\implies 3
\\\\\\
\textit{one can also say that}\qquad 5=\sqrt[2]{5^2}~~or~~3=\sqrt[3]{3^3}\\\\
-------------------------------[/tex]
[tex]\bf therefore\qquad 8.485281374=
\begin{cases}
\sqrt[2]{8.485281374^2}\\\\ \sqrt[3]{8.485281374^3}\\\\
\sqrt[7]{8.485281374^7}\\\\
\sqrt[11]{8.485281374^{11}}\\\\
\sqrt[x]{8.485281374^x}
\end{cases}\impliedby \textit{any is valid}
\\\\\\
\textit{so say then}\qquad 8.485281374=\sqrt[2]{8.485281374^2}
\\\\\\
8.485281374=\sqrt{71.999999995951327876}[/tex]
