\[\boxed{Стр.\ \mathbf{46}\text{.\ \ }\mathbf{ОК\ ГДЗ\ - \ домашка\ на\ 5}}\]
\[\boxed{\mathbf{1}.}\]
\[47 + 30 = 77\]
\[Ответ:неверно.\]
\[\boxed{\mathbf{2}.}\]
\[32 - 8 = 24\]
\[Ответ:верно.\]
\[\boxed{\mathbf{3}.}\]
\[76 + 7 = 83\]
\[Ответ:верно.\]
\[\boxed{\mathbf{4}.}\]
\[89 - 50 = 39\]
\[Ответ:неверно.\]
\[\boxed{\mathbf{5}.}\]
\[Ответ:верно.\]
\[\boxed{\mathbf{6}.}\]
\[68 + 4 = 72\]
\[72 - 4 = 68\]
\[Ответ:неверно.\]
\[\boxed{\mathbf{7}.}\]
\[60 - 3 = 57\]
\[57 + 3 = 60\]
\[Ответ:верно.\]
\[\boxed{\mathbf{8}.}\]
\[34 - 9 = 25\]
\[Ответ:верно.\]
\[\boxed{\mathbf{9}.}\]
\[80 - (20 + 8) = 80 - 20 - 8\]
\[Ответ:неверно.\]
\[\boxed{\mathbf{10}.}\]
\[86 - 30 = 56\]
\[30 + 26 = 56\]
\[86 - 30 = 30 + 26\]
\[Ответ:неверно.\]
\[\boxed{\mathbf{11}.}\]
\[(50 + 25) - (50 - 25) =\]
\[= 75 - 25 = 50\]
\[Ответ:верно.\]
\[\boxed{\mathbf{12}.}\]
\[40 - 6 = 34\]
\[35 - 1 = 34\]
\[Ответ:верно.\]