1-ая труба (что-то делает) дольше чем 2-ая труба на 55 минут, вместе они (что-то делают) за 24

1-ая труба (что-то делает) дольше чем 2-ая труба на 55 минут, вместе они (что-то делают) за 24 минуты. Сколько минут (что-то делает) 2-ая труба?
- Предмет:
  Математика
- Автор:
  reed
- 6 лет назад

Ответы 1

х минут вторая труба(х+55) минут - первая1/24 часть обе за 1 мин1/х часть вторая за 1 мин1/(х+55) первая1/х+1/(х+55)=1/24 (умножим на 24х(х+55))24(х+55)+24х=х(х+55)24х+1320+24х=х^2+55хх^2+7х-1320=0D=7*7-4(-1320)=49+5280=5329 Корень из D=73х(1)=(-7-73):2=-80:2=-40 (не подходит)х(2)=(-7+73):2=66:2=33 (мин)Ответ: вторая делает что-то за 33 минуты
- Автор:
  queen beefown
- 6 лет назад
- 0
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1-ая труба (что-то делает) дольше чем 2-ая труба на 55 минут, вместе они (что-то делают) за 24 минуты. Сколько минут (что-то делает) 2-ая труба?

Ответы 1

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