Есть вот,но это я писала когда ездила в Испанию!! I would like to tell you about my trip to Spain last summer. I think that it was the most interesting trip in my life. I travelled there with my parents.
The nature in Spain is very beautiful, and all trees were green when we came there. I saw the deep and blue sea, and I wanted to swim. But on the third day of our staying in Spain we saw dark clouds, and so we decided to go sightseeing around the town. There I saw real Spain’s life. It was very attractive to me.
During the first week of our trip we only swam in the sea. It was very warm with large waves. Near the rocks there were a lot of different fishes, and all the tourists watched them. One day we went on the excursion. It was the excursion to the Salvador Dali Museum – a famous Spanish painter. We went to his castle and admired his garden around it. There were many trees and beautiful flowers. But the main purpose of our trip was to see his paintings. All the pictures are very unusual and strange. But this mystery is a drop of real art. And what his moustaches are! We also saw his wife in his paintings. So I can say that the excursion was amazing. Near the castle we saw a field of sunflowers. It was all yellow and very beautiful. After the excursion we went to a Spanish cafe. There we tasted delicious pasta.
Я не люблю такие задачи "Через икс" решать, но табличку не составить. Придётся. м1 = 0,4*9 = 3, 6 литров чистого вещества (например, соли или кислоты) в первом растворе м2 = 0,2*11 = 2,2 литров чистого вещества во 2-м растворе м12 = х*(9+11) = 20*х литров чистого вещества в смеси растворов, где х - это дробь, какую часть составляет чистое вещество в смеси от общей массы смеси = 20 литров. Далее - закон сохранения массы: сколько чистого вещества в каждом из растворов - столько же и в их сумме, т.е. уравнение: м1 + м2 = м12 - подставляем: 3, 6 + 2, 2 = 20*х 5,8 = 20*х х = 5,8/20 =0,29 В процентах 0,29 = 29%. А вообще-то лучше поискать в инете аналогичную задачу, найти для себя понятную и разобраться с ней. А то ведь не всегда ж можно рассчитывать на Ищите и обрящете!
The nature in Spain is very beautiful, and all trees were green when we came there. I saw the deep and blue sea, and I wanted to swim. But on the third day of our staying in Spain we saw dark clouds, and so we decided to go sightseeing around the town. There I saw real Spain’s life. It was very attractive to me.
During the first week of our trip we only swam in the sea. It was very warm with large waves. Near the rocks there were a lot of different fishes, and all the tourists watched them. One day we went on the excursion. It was the excursion to the Salvador Dali Museum – a famous Spanish painter. We went to his castle and admired his garden around it. There were many trees and beautiful flowers. But the main purpose of our trip was to see his paintings. All the pictures are very unusual and strange. But this mystery is a drop of real art. And what his moustaches are! We also saw his wife in his paintings. So I can say that the excursion was amazing. Near the castle we saw a field of sunflowers. It was all yellow and very beautiful. After the excursion we went to a Spanish cafe. There we tasted delicious pasta.
м1 = 0,4*9 = 3, 6 литров чистого вещества (например, соли или кислоты) в первом растворе
м2 = 0,2*11 = 2,2 литров чистого вещества во 2-м растворе
м12 = х*(9+11) = 20*х литров чистого вещества в смеси растворов, где х - это дробь, какую часть составляет чистое вещество в смеси от общей массы смеси = 20 литров.
Далее - закон сохранения массы: сколько чистого вещества в каждом из растворов - столько же и в их сумме, т.е. уравнение:
м1 + м2 = м12 - подставляем:
3, 6 + 2, 2 = 20*х
5,8 = 20*х
х = 5,8/20 =0,29
В процентах 0,29 = 29%.
А вообще-то лучше поискать в инете аналогичную задачу, найти для себя понятную и разобраться с ней. А то ведь не всегда ж можно рассчитывать на Ищите и обрящете!