\[\boxed{\mathbf{Проверьте\ себя.\ Страница\ 23}}\]
\[\boxed{\mathbf{Проверочная\ работа.\ Модуль\ числа}}\]
\[\boxed{\mathbf{1.}}\]
\[0.\]
\[\boxed{\mathbf{2.}}\]
\[| - 6| = 6.\]
\[\boxed{\mathbf{3.}}\]
\[|70| = 70.\]
\[\boxed{\mathbf{4.}}\]
\[|a| = 11\]
\[a = \pm 11.\]
\[\boxed{\mathbf{5.}}\]
\[|c| = 7;\]
\[| - c| = 7.\]
\[\boxed{\mathbf{6.}}\]
\[\mathbf{Нет.}\]
\[\mathbf{Один\ корень:}\]
\[|x| = 0\]
\[x = 0.\]
\[\boxed{\mathbf{7.}}\]
\[\mathbf{Да.}\]
\[\boxed{\mathbf{8.}}\]
\[\mathbf{Да.}\]