In the evenings into the city and go clubbing or see a movie. a lot of new friends. my pronunciation is much better already, and almost everything. On weekdays Liam. At the moment on their new website and help with it. some useful stuff about how people business in this country.
to see me? the winter holiday skiing with Ryan and Liam. to meet you and there’s plenty of space. You must bring lots of warm clothes because really cold here in the winter. Let me know as soon as . And tell me what these days.
In the evenings into the city and go clubbing or see a movie. a lot of new friends. my pronunciation is much better already, and almost everything. On weekdays Liam. At the moment on their new website and help with it. some useful stuff about how people business in this country.
to see me? the winter holiday skiing with Ryan and Liam. to meet you and there’s plenty of space. You must bring lots of warm clothes because really cold here in the winter. Let me know as soon as . And tell me what these days.
Пусть масса 43-процентного раствора кислоты - m1 кг, а масса 49-процентного - m2.
Это реашется очень просто, выучи алгоритм.
Если смешать 43-процентный и 49-процентный растворы кислоты и добавить 10 кг чистой воды, получится 27-процентный раствор кислоты: 0,43m1 + 0,49m2 = 0,27 (m1 + m2 +10).
Если бы вместо 10 кг воды добавили 10 кг 50-процентного раствора той же кислоты, то получили бы 47-процентный раствор кислоты: 0,43m1 + 0,49m2 + 0,5 * 10 = 0,49 (m1 + m2 +10).
Решим полученную систему уравнений:
Верхняя строчка: 0,43m1 + 0,49m2 = 0,27m1 + 0,27m2 + 2,7
Нижняя строчка: 0,43m1 + 0,49m2 + 5 = 0,49m1 + 0,49m2 + 4,9
И решаешь систему, одно выражаешь через другое.