Answer
$\dfrac{8x^{12}}{27}$
Work Step by Step
RECALL:
(i) $(ab)^m = a^mb^m$
(ii) $\left(\dfrac{a}{b}\right)^m=\dfrac{a^m}{b^m}$
(iii) $(a^m)^n=a^{mn}$
Use the rules above to have:
$=\dfrac{2^3(x^4)^3}{3^3}
\\=\dfrac{8x^{4(3)}}{27}
\\=\dfrac{8x^{12}}{27}$