\[\boxed{\mathbf{4.}\mathbf{72}}\]
\[\textbf{а)}\ |x| = 8,1\]
\[x = \pm 8,1.\]
\[\textbf{б)}\ |x| = 7\]
\[x = \pm 7.\]
\[\textbf{в)}\ |x| = 0\]
\[x = 0.\]
\[\textbf{г)}\ |x| = \frac{5}{12}\]
\[x = \pm \frac{5}{12}.\]
\[\textbf{д)}\ |x| = - 1\]
\[нет\ корней.\]