Предмет: Математика, автор: polinabahlovskaa

у Ани 35 монет по 2 руб и 5 руб причём сумма денег в 2 рублевых монетах равна сумме денег пятирублёвых монетах сколько они пятирублёвых монет?​

Ответы

Автор ответа: pushpull
6

Ответ:

пятирублевых монет было 10 штук.

Пошаговое объяснение:

Пусть монет по 5руб                                   х штук;

тогда сумма всех пятирублевых монет   5х рублей.

Монет по 2руб будет                             (35-х) штук;

сумма всех двухрублевых монет       2(35-х) рублей

По условию задачи эти суммы равны.

Составим уравнение и решим его

5х = 2(35-х)

5х = 70 - 2х

7х =  70

х = 10

Вернемся к нашим обозначениям и получим ответ:

пятирублевых монет было 10 штук.

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