\(\left|x^2-5\right|+\left|5-x^2\right|=40\)
\(\left|x^2-5\right|+\left|x^2-5\right|=40\)
\(2.\left|x^2-5\right|=40\)
\(\left|x^2-5\right|=20\)
\(\Rightarrow\left[{}\begin{matrix}x^2-5=20\\x^2-5=-20\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x^2=25\\x^2=-25\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=5\\x=-5\end{matrix}\right.\)
Vậy : .....
\(\left|x^2-5\right|+\left|5-x^2\right|=40\)
\(\Leftrightarrow\left|x^2-5\right|+\left|x^2-5\right|=40\)
\(\Leftrightarrow2.\left|x^2-5\right|=40\)
\(\Leftrightarrow\left|x^2-5\right|=20\)
\(\Leftrightarrow\left[{}\begin{matrix}x^2-5=20\\x^2-5=-20\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x^2=25\\x^2=-15\end{matrix}\right.\)
Vì \(x^2\) luôn là số nguyên dương.
\(\Leftrightarrow x^2=25\)
\(\Leftrightarrow x=\pm5\)
Vậy \(x=\pm5\) thì \(\left|x^2-5\right|+\left|5-x^2\right|=40\)
Chúc bạn học tốt!
