Answer
$d= -9$, $d= 9$
Work Step by Step
Given \begin{equation}
7 d^4=45927.
\end{equation} We solve the equation: \begin{equation}
\begin{aligned}
7 d^4&=45927\\
d^4&=\frac{45927}{7}\\
d^4&=6561\\
d & =\pm\sqrt[4]{6561} \\
& =\pm 9.
\end{aligned}
\end{equation} The solution is $d= -9$, $d= 9$.
