\[\mathbf{Страница\ 25.}\]
\[\boxed{\mathbf{4.}}\]
\[\textbf{а)}\ 28\ 080\]
\[\textbf{б)}\ 11\ 208\]
\[\textbf{в)}\ 976\]
\[\textbf{г)}\ 7\ 698\ 998\]
\[\boxed{\mathbf{5.}}\]
\[\textbf{а)}\ x - 5041 = 3269\]
\[x = 3269 + 5041\]
\[x = 8310.\]
\[Ответ:\ 8310.\]
\[\textbf{б)}\ 20\ 305 - x = 15\ 408\]
\[x = 20\ 305 - 15\ 408\]
\[x = 4897.\]
\[Ответ:\ 4897.\]
\[\boxed{\mathbf{6.}}\]
\[\textbf{а)}\]
\[\textbf{б)}\]
\[\textbf{в)}\ \]
\[\boxed{\mathbf{7.}}\]
\[\boxed{\mathbf{8.}}\]
\[\textbf{а)}\ 42\ 851 + 37\ 168 - 74\ 018 =\]
\[= 6001\]
\[\textbf{б)}\ 70\ 600 - (2348 - 897) =\]
\[= 69\ 149\]
\[\textbf{в)}\ 35\ 270 - (4060 + 1978) =\]
\[= 29\ 232\]