Решебник по математике 5 класс Алышева Нахождение неизвестного вычитаемого Задание 8

\[\boxed{\mathbf{8.}}\]

\[\textbf{а)}\ x - 40 = 35\]

\[x = 35 + 40\]

\[x = 75.\]

\[Проверка.\]

\[75 - 40 = 35\]

\[35 = 35.\]

\[40 - x = 35\]

\[x = 40 - 35\]

\[x = 5.\]

\[Проверка.\]

\[40 - 5 = 35\]

\[35 = 35.\]

\[66 - x = 20\]

\[x = 66 - 20\]

\[x = 46.\]

\[Проверка.\]

\[66 - 46 = 20\]

\[20 = 20.\]

\[x - 66 = 20\]

\[x = 20 + 66\]

\[x = 86.\]

\[Проверка.\]

\[86 - 66 = 20\]

\[20 = 20.\]

\[\textbf{б)}\ x - 55 = 17\]

\[x = 17 + 55\]

\[x = 72.\]

\[Проверка.\]

\[72 - 17 = 55\]

\[55 = 55.\]

\[55 - x = 17\]

\[x = 55 - 17\]

\[x = 38.\]

\[Проверка.\]

\[55 - 38 = 17\]

\[17 = 17.\]