Answer
$\displaystyle \frac{1}{3}(x^{2}+4)^{1/3}(11x^{2}+12)=\frac{1}{3}\sqrt[3]{(x^{2}+4)}(11x^{2}+12)$
Work Step by Step
We simplify:
$(x^{2}+4)^{4/3}+x\displaystyle *\frac{4}{3}(x^{2}+4)^{1/3}* 2x=(x^{2}+4)^{1/3}((x^{2}+4)^{3/3}+\frac{8}{3}x^{2})=(x^{2}+4)^{1/3}(x^{2}*\frac{3}{3}+4+\frac{8}{3}x^{2})=(x^{2}+4)^{1/3}(\frac{11}{3}x^{2}+4)=
\frac{1}{3}(x^{2}+4)^{1/3}(11x^{2}+12)=\frac{1}{3}\sqrt[3]{(x^{2}+4)}(11x^{2}+12)$
