Question

(31•550-икс)•120=10200

Answer 1

17050-х=10200:120
17050-х=85
х=85-17050
х=-16965

Answer 2

(31*550-x)*120=10200

(17050-x)*120=10200

2046000-120x=10200

-120x=10200-2046000

-120x=-2035800 | : (-120)

x=16965