9.047. $\frac{x^{4}+x^{2}+1}{x^{2}-4 x-5}<0$.

9.047. $\frac{x^{4}+x^{2}+1}{x^{2}-4 x-5}<0$.
## Solution.

Since $x^{4}+x^{2}+1>0$ for $x \in R$, we have $x^{2}-4 x-5<0$, $(x+1)(x-5)<0, -1<x<5$.

Answer: $\quad x \in(-1 ; 5)$.