Question

\[\sqrt[3]{28x}=-4\]

Answer 1

\[\sqrt[3]{28x}=-4\]

Answer 2

$$
\large{
\sqrt[3]{28x}=-4\\
28x=(-4)^{1/3}\\
x=\cfrac{(-4)^{1/3}}{28}\\
=2^{2/3}\times\sqrt[3]{-1}~
}
$$
Does that help?

Answer 3

Not really @ybarrap