Ta có: \(\frac{x}{113}=\frac{113}{x}\) <=> \(x^2=12769\)
<=> \(x=\sqrt{12769}\)
<=> \(\left[\begin{matrix}x=113 \left(ko thỏa mãn\right)\\x=-113 \left(thỏa mãn x< 0\right)\end{matrix}\right.\)
Vậy x=-113
Giá trị x < 0 thỏa mãn : \(\frac{x}{113}=\frac{113}{x}\)
Ta có : \(\frac{x}{113}=\frac{113}{x}\Leftrightarrow-x^2=-113^2\)
\(-x^2=-113^2\Rightarrow-x=113\)
\(\frac{x}{113}=\frac{113}{x}\)
\(\Rightarrow x^2=12769\)
mà x < 0
\(\Rightarrow x=-113\)