Answer
$\lim\limits_{x \to -6^+} \sqrt[8] {6+x} = 0$
Work Step by Step
Let $\epsilon \gt 0$ be given.
Let $\delta = \epsilon^8$
Suppose that $\vert x-(-6) \vert \lt \delta$.
Then: $\vert \sqrt[8] {6+x}-0 ~\vert \lt \sqrt[8] \delta = \sqrt[8] \epsilon^8 = \epsilon$
Therefore, $\lim\limits_{x \to -6^+} \sqrt[8] {6+x} = 0$