Tập nghiệm của bất phương trình

* Hướng dẫn giải

Điều kiện: $x\ne 0$

$$\begin{gathered} (2^{x^2-4}-1)ln{x}^2<0\Rightarrow \left[\begin{array}{c}\left\{\begin{array}{c}(2^{x^2-4}-1)>0\\ ln{x}^2<0\end{array}\right.\\ \left\{\begin{array}{c}(2^{x^2-4}-1)<0\\ ln{x}^2>0\end{array}\right.\end{array}\right. \\ \begin{array}{l}\iff \left[\begin{array}{c}\left\{\begin{array}{c}{2}^{x^2-4}>1\\ x^2<1\end{array}\right.\\ \left\{\begin{array}{c}{2}^{x^2-4}<1\\ x^2>1\end{array}\right.\end{array}\right.\iff \left[\begin{array}{c}\left\{\begin{array}{c}{x}^2-4>0\\ x^2<1\end{array}\right.\\ \left\{\begin{array}{c}{x}^2-4<0\\ x^2>1\end{array}\right.\end{array}\right.\\ \iff \left[\begin{array}{c}\left\{\begin{array}{c}x>2;x<-2\\ -1<x<1\end{array}\right.\\ \left\{\begin{array}{c}-2<x<2\\ x>1;x<-1\end{array}\right.\end{array}\right.\iff \left[\begin{array}{c}-2<x<-1\\ 1<x<2\end{array}\Rightarrow x\in (-2;-1)\cup (1;2)\right.\end{array} \end{gathered}$$

Đáp án cần chọn là: B