Question

(580:b-25) •90+490=850

Answer 1

580:b-25)*90=850-490

(580:b-25)*90=360

580:b-25=360:90

580:b-25=4

580:b=25+4

580:b=29

b=580:29

b=20

Ответ:20

Answer 2

It looks like there might be a misunderstanding in your input. $580:b-25$ is not a valid mathematical expression. If you could provide a clear and complete expression, I'd be happy to help you solve it!