Пусть х км/ч - скорость течения реки, тогда (6 + х) км/ч - скорость катера по течению реки, (6 - х) км/ч - скорость катера против течения реки. Уравнение:
My name is Sergei. I want to tell about my family. My family consists of five people: mom, dad, grandma, grandpa and me. My mother's name is Irina, Igor papu- Venediktovich, babushku- Valentina, dedushku- Vasili Alexandrovich. My mom and dad went abroad in the summer. My grandmother likes to knit. A grandfather likes to help her in some kind of business.
I love my family so that she loves me all. (Option 1) My family.
I want to tell you about my favorite family. My family consists of mom, dad and me. My mother's name is Elena, father - Andrei Vladimirovich. Mom stays at home, it does not work, and my father is the director of the store. Mom knows and loves to knit. With Dad I'm a little vizhus because he works very hard. We have a cottage, and two dogs in the country. For dogs have to look. We as a family went to the United Arab Emirates. It was very interesting there. We swam in the sea, in the pool, sunbathing on the beach. We sailed on the ship. They dive straight from the ship. Only my dad diving and many other adults, because the ship was sailing slowly. Even in the United Arab Emirates, we went on a jeep. This excursion called "Jeep Safari". At the jeep we drove on the sand in the desert. There were camel thorns and some more beautiful, but poisonous plant. Me and my family was very interesting and fun. I'm having a good time with his family. I love my family. ( Option 2)
S = 16 км - расстояние между пристанями
40 мин = 40/60 ч = 2/3 ч - время стоянки
t = 6 2/3 - 2/3 = 6 ч - время движения
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Пусть х км/ч - скорость течения реки, тогда (6 + х) км/ч - скорость катера по течению реки, (6 - х) км/ч - скорость катера против течения реки. Уравнение:
16/(6+х) + 16/(6-х) = 6
16 · (6 - х) + 16 · (6 + х) = 6 · (6 - х) · (6 + х)
96 - 16х + 96 + 16х = 6 · (6² - х²)
192 = 216 - 6х²
192 - 216 + 6х² = 0
6х² - 24 = 0 | разделим обе части уравнения на 6
х² - 4 = 0
х² = 4
х = √4
х₁ = 2 и х₂ = -2 (не подходит, так как < 0)
ответ: 2 км/ч - скорость течения.
Проверка:
16 : (6 + 2) + 16 : (6 - 2) = 16 : 8 + 16 : 4 = 2 + 4 = 6 ч - время движения
My name is Sergei. I want to tell about my family. My family consists of five people: mom, dad, grandma, grandpa and me. My mother's name is Irina, Igor papu- Venediktovich, babushku- Valentina, dedushku- Vasili Alexandrovich. My mom and dad went abroad in the summer. My grandmother likes to knit. A grandfather likes to help her in some kind of business.
I love my family so that she loves me all.
(Option 1)
My family.
I want to tell you about my favorite family. My family consists of mom, dad and me. My mother's name is Elena, father - Andrei Vladimirovich. Mom stays at home, it does not work, and my father is the director of the store. Mom knows and loves to knit. With Dad I'm a little vizhus because he works very hard. We have a cottage, and two dogs in the country. For dogs have to look. We as a family went to the United Arab Emirates. It was very interesting there. We swam in the sea, in the pool, sunbathing on the beach. We sailed on the ship. They dive straight from the ship. Only my dad diving and many other adults, because the ship was sailing slowly. Even in the United Arab Emirates, we went on a jeep. This excursion called "Jeep Safari". At the jeep we drove on the sand in the desert. There were camel thorns and some more beautiful, but poisonous plant. Me and my family was very interesting and fun. I'm having a good time with his family. I love my family.
( Option 2)