1) (223440 - 130 * х ) : 35 = 6 020
223440 - 130 * х = 6020 * 35
223440 - 130 * х = 210700
130 * х = 223440 - 210700
130 * х = 12740
х = 12740 : 130
х = 98
Проверяем:
(223440 - 130 * 98) : 35 = 6020
(223440 - 12740) : 35 = 6020
210700 : 35 = 6020
6020 = 6020
2) (31 * 550 - x) * 120 = 10200
31 * 550 - x = 10200 : 120
31 * 550 - x = 85
17050 - х = 85
х = 17050 - 85
х = 16965
Проверяем:
(31 * 550 - 16965 ) * 120 = 10200
(17050 - 16965) * 120 = 10200
85 * 120 = 10200
10200 = 10200