Сделай деяния и найди неизвестное. Только 3 номер

Ответ:

3

789 + x = 20 * 30 + 9

x = 600 + 9 - 789

x = 609 - 789

x = - 180;

x - 4340 / 10 = 897 - 203

x - 434 = 897 - 203

x = 897 - 203 + 434

x = 1128;

(384 + 474) - x = 40 * 20

858 - x = 600

- x = 600 - 858

- x = - 258

x = 258;

x + 13 * 50 = 847 + 925

x + 650 = 847 + 925

x = 847 + 925 - 650

x = 1122

Задание 3

789 + x = 20 * 30 + 9

x = 600 + 9 - 789

x = 609 - 789

x = - 180;

x - 4340 / 10 = 897 - 203

x - 434 = 897 - 203

x = 897 - 203 + 434

x = 1128;

(384 + 474) - x = 40 * 20

858 - x = 600

- x = 600 - 858

- x = - 258

x = 258;

x + 13 * 50 = 847 + 925

x + 650 = 847 + 925

x = 847 + 925 - 650

x = 1122;