(223440-130*x)/35=6020

223440-130*x=6020*35

223440-130*x=210700

-130*x=210700-223440

-130*x=-12740

x=-12740/-130

х=98

(31*550-x)*120=10200

31*550-x=10200/120

17050-x=85

-x=85-17050

-x=-16965

x=16965