Question

(31*550-х)*120=10200

Answer 1

(31*550-х)*120=10200

31*550-х=10200/120

17050-х=85

х=17050-85

х=16965

проверка

(31*550--16965)*120=10200

(17050-16965)*120=10200

85*120=10200

10200=10200