от пристаней,расстояние между которыми по реке 640 км,вышли одновременно навстречу друг

от пристаней,расстояние между которыми по реке 640 км,вышли одновременно навстречу друг другу два теплохода.Собственная скорость теплоходов одинакова.Скорость течения реки 2 км / ч.Теплоход,идущий по течению,за 9 часов проходит 198 км.Через сколько часов теплоходы встретятся?
- Предмет:
  Математика
- Автор:
  calhoun
- 6 лет назад

Ответы 1

определим скорость теплохода:(v+2)*9=198(v-скорость теплохода)9v+18=198v=198/9=20рассчитаем через какое время встретятся теплоходы(20+2)t=x(20-2)t=yx+y=640(20+2)*t+(20-2)*t=640t(20+2+20-2)=640t=16 ч
- Автор:
  noahfjua
- 6 лет назад
- 0
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