\[\boxed{Стр.\ \mathbf{13}\text{.\ \ }\mathbf{ОК\ ГДЗ\ - \ домашка\ на\ 5}}\]
\[\boxed{\mathbf{1}.}\]
\[\boxed{\mathbf{2}.}\]
\[36 + 9 = 36 + 4 + 5 = 40 + 5 = 45\]
\[45 - 9 = 45 - 5 - 4 = 40 - 4 = 36\]
\[92 - 8 = 92 - 2 - 6 = 90 - 6 = 84\]
\[84 + 8 = 84 + 6 + 2 = 90 + 2 = 90\]
\[\boxed{\mathbf{3}.}\]
\[15 - 8 = 7\ (яхт) - вышли\ в\ море.\]
\[Ответ:7\ яхт.\]
\[\boxed{\mathbf{4}.}\]
\[1)\ 16 - 7 = 9\ (яхт) - маленьких.\]
\[2)\ 16 + 9 = 25\ (яхт) - вышло\ \]
\[в\ море.\]
\[Ответ:25\ яхт.\]
\[\boxed{\mathbf{5}.}\]
\[30 - x = 20\]
\[x = 30 - 20\]
\[x = 10.\]
\[x + 1 = 40\]
\[x = 40 - 1\]
\[x = 39.\]
\[y - 8 = 7\]
\[y = 7 + 8\]
\[y = 15.\]
\[\boxed{\mathbf{6}.}\]
\[26 + 7 = 33\]
\[38 + 4 = 42\]
\[42 + 9 = 51\]
\[60 - 38 = 22\]
\[70 - 27 = 43\]
\[80 - 16 = 64\]
\[14 = 1\ дес.\ 4\ ед.\]
\[40 = 4\ дес.\ 0\ ед.\]
\[19 = 1\ дес.\ 9\ ед.\]
\[\boxed{\mathbf{Вопрос}.}\]
\[\boxed{\mathbf{Задание\ на\ полях}.Продолжи\ ряд\ чисел\ }\]
\[Сначала\ прибавляют\ 2,\ потом\ 4,\ \]
\[потом\ каждый\ раз\ на\ 2\ больше:\]
\[1,\ 3,\ 7,\ 13,\ 21,\ 31,\ 43,\ 57\ .\]