Answer
$\color{blue}{\dfrac{2\sqrt{x^2}}{x^2}}$
Work Step by Step
Rationalize the denominator by multiplying $x^2$ to both the numerator and denominator of the radicand to obtain:
$=\sqrt[3]{\dfrac{8(x^2)}{x^4(x^2)}}
\\=\sqrt[3]{\dfrac{8x^2}{x^6}}
\\=\sqrt[3]{\dfrac{8x^2}{(x^2)^3}}$
Bring out the cube root of the denominator to obtain:
$\\=\dfrac{\sqrt[3]{8x^2}}{x^2}$
Factor the radicand such that at least one factor is a perfect cube to obtain:
$\\=\dfrac{\sqrt[3]{(8(x^2)}}{x^2}
\\=\dfrac{\sqrt{(2)^3(x^2)}}{x^2}$
Bring out the cube root of the perfect cube factor/s of the numerator to obtain:
$\\=\color{blue}{\dfrac{2\sqrt{x^2}}{x^2}}$