Question

Вес сосновой шпалы 27,8 кг,а дубовой 45,5 кг.Вес 10 доставленных шпал равен 384,2 кг. Сколько среди этих шпал сосновых и сколько дубовых.

Answer 1

Количество сосновых шпал Х штук
Количество дубовых шпал (10-Х) шт.
Вес всех сосновых шпал =27,8Х (кг)
вес всех дубовых шпал = 45,5(10-Х) кг
Уравнение:
27,8Х + 45,5(10 - Х) = 384,2
27,8Х + 455 -45,5Х = 384,2
- 17,7Х = -455+ 384,2
   17,7Х = 70,8
           Х = 4
     10 - 4 = 6
Ответ: 4 сосновых шпалы, 6 дубовых шпал.

Answer 2

Calculating the Number of Pine and Oak Sleepers

To solve this problem, we can use a system of linear equations. Let's denote the number of pine sleepers as x and the number of oak sleepers as y.

We have the following information: 1. The weight of a pine sleeper is 27.8 kg. 2. The weight of an oak sleeper is 45.5 kg. 3. The total weight of 10 sleepers is 384.2 kg.

We can express this information as a system of equations: - 27.8x + 45.5y = 384.2 (total weight equation) - x + y = 10 (total number of sleepers equation)

Solving the System of Equations

We can solve this system of equations to find the values of x and y.

First, let's solve the second equation for x: x = 10 - y

Now, we can substitute this expression for x into the first equation: 27.8(10 - y) + 45.5y = 384.2

Expanding and simplifying: 278 - 27.8y + 45.5y = 384.2 278 + 17.7y = 384.2 17.7y = 106.2 y = 6

Substitute y = 6 back into x = 10 - y: x = 10 - 6 x = 4

Answer:

So, there are 4 pine sleepers and 6 oak sleepers among the 10 sleepers.