Question

Решите уравнение: ||x| -9| = 3​

Answer 1

||x|-9|=3

$\left[\begin{array}{cc}|x|-9=3\\\\|x|-9=-3\end{array} \Longrightarrow \left[\begin{array}{cc}|x|=12\\\\|x|=6\end{array} \Longrightarrow \boxed {x= \pm 12;\pm 6}$