#### Answer

$x^{12}$

#### Work Step by Step

We are given the expression $(x^{3})^{4}$.
To simplify, we can use the power rule, which holds that $(a^{m})^{n}=a^{m\times n}$ (where a is a real number, and m and n are integers).
$(x^{3})^{4}=x^{3\times4}=x^{12}$