Предмет: Математика, автор: kulgashowa11

придумайте текст задачи по этому уравнению 3⋅(x+3)+4⋅(x−3)=109 пожалуйста

Ответы

Автор ответа: vmaluga2011
0
Катер шел по течению 3 часа, а против течения 4 часа. Всего он прошел 109 км. Какая собственная скорость катера, если скорость течения равна 3 км/ч?

х - собственная скорость катера
х+3 - скорость по течению
х-3 - скорость против течения
3(х+3)+4(х-3)=109
3х+9+4х-12=109
3х+4х=109-9+12
7х=112
х=112:7
х=16 (км/ч)
Ответ: собственная скорость катера равна 16 км/ч
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D.I. MENDELEYEV (1834-1907)

1. A Russian name appeared in 1964 on the honorary board of science at
Bridgeport University, USA: Mendeleyev was added to the list of the greatest
geniuses - Euclid, Archimedes, Copernicus, Galilei, Newton and Lavoisier. D.I,
Mendeleyev, the explorer of nature, is the greatest chemist of the world. The
Mendeleyev system has served for almost 100 years as a key to discovering new
elements and it has retained its key capacity until now.
2. D.I. Mendeleyev was the fourteenth, and last child of the Director of
the gymnasium at Tobolsk. At 16 he was taken by his mother to St.Petersburg to
seek higher education. He entered the Pedagogical Institute where his father has
also studied. In 1856 he took a degree in chemistry and in 1859 he was sent
abroad for two years for further training. He returned to St.Petersburg in 1861 as
Professor of Chemistry.
3. In 1868 Mendeleyev began to write a great textbook of chemistry,
known in its English translation as the "Principles of Chemistry". In compiling
this, he tried to find some system of classifying the elements - some sixty in all
then known - whose properties he was describing. This led him to formulate the
Periodic Law, which earned him lasting international fame. He presented it verbally to the Russian Chemical Society in October 1868 and published it in February 1869.
4. In this paper he set out clearly his discovery that if the elements are arranged in order of their atomic weights, chemically related elements appear at
regular intervals.
The greatness of Mendeleyev's achievement lies in the fact that he had
discovered a generalization that not only unified an enormous amount of existing information but pointed the way to further progress.