Решебник по математике 5 класс Алышева Тысяча Задание 192

\[\boxed{\mathbf{192.}}\]

\[x + 200 = 600\]

\[x = 600 - 200\]

\[x = 400.\]

\[Проверка.\]

\[400 + 200 = 600\]

\[600 = 600.\]

\[300 + x = 850\]

\[x = 850 - 300\]

\[x = 550.\]

\[Проверка.\]

\[300 + 550 = 850\]

\[850 = 850.\]

\[305 - x = 300\]

\[x = 305 - 300\]

\[x = 5.\]

\[Проверка.\]

\[305 - 5 = 300\]

\[300 = 300.\]

\[x - 400 = 120\]

\[x = 120 + 400\]

\[x = 520.\]

\[Проверка.\]

\[520 - 400 = 120\]

\[120 = 120.\]