Answer
$\frac{1}{x^{7}}$
Work Step by Step
According to the power rule for exponents, $(a^{m})^{n}=a^{mn}$ (where $m$ and $n$ are integers and $a$ is a real number).
Therefore, $(x^{3})^{-4}x^{5}=x^{3\times-4}x^{5}=x^{-12}x^{5}$.
According to the product rule for exponents, $a^{m}\times a^{n}=a^{m+n}$.
Therefore, $x^{-12}x^{5}=x^{-12+5}=x^{-7}$.
According to the negative definition for exponents, $a^{-n}=\frac{1}{a^{n}}$ (where $a\ne0$).
Therefore, $x^{-7}=\frac{1}{x^{7}}$.