Đáp án + giải thích các bước giải:
`(x^2-13)(x^2-17)<0`
`->`$\left\{\begin{matrix} x^2-13>0\\x^2-17<0 \end{matrix}\right.$
`->`$\left\{\begin{matrix} (x-\sqrt{13})(x+\sqrt{13})>0\\(x-\sqrt{17})(x+\sqrt{17})<0 \end{matrix}\right.$
`->`$\left\{\begin{matrix} \left[ \begin{array}{l}\left\{\begin{matrix} x-\sqrt{13}>0\\x+\sqrt{13}>0 \end{matrix}\right.\\\left\{\begin{matrix} x-\sqrt{13}<0\\x+\sqrt{13}<0 \end{matrix}\right.\end{array} \right.\\\left\{\begin{matrix} x+\sqrt{17}>0\\x-\sqrt{17}<0 \end{matrix}\right. \end{matrix}\right.$
`->`$\left\{\begin{matrix} \left[ \begin{array}{l}\left\{\begin{matrix} x>\sqrt{13}\\x>-\sqrt{13} \end{matrix}\right.\\\left\{\begin{matrix} x<\sqrt{13}\\x<-\sqrt{13} \end{matrix}\right.\end{array} \right.\\\left\{\begin{matrix} x>-\sqrt{17}\\x<\sqrt{17} \end{matrix}\right. \end{matrix}\right.$
`->`$\left\{\begin{matrix} \left[ \begin{array}{l}x>\sqrt{13}\\x<-\sqrt{13}\end{array} \right.\\-\sqrt{17}<x<\sqrt{17} \end{matrix}\right.$
`->`\(\left[ \begin{array}{l}-\sqrt{17}<x<-\sqrt{13}\\\sqrt{13}<x<\sqrt{17}\end{array} \right.\)
