Question

В мастерскую школы привезли 28 сломаных стульев с одной,с двумя и тремя ножками.ребята нащитали всего 51 ножку.Сколько стульев с тремя ножками принесли в мастерскую,если стульев с одной ножкой столько,сколько стульев с тремя и с двумя ножками?

Answer 1

Пусть трехногих  х стульев, двуногих у тогда одноногих 28/2=14 и всего их 28.
Ножек у трехногих 3х, у двуногих 2у, у одноногих 14 и всего 51 ножка
Получаем систему уравнений:
х+у+14=28
3х+2у+14=51  

х+у=28-14
3х+2у=51-14  

х+у=14
3х+2у=37
Выразим из первого уравнения у:
у=14-х
и подставим полученное выражение во второе:
3х+2(14-х)=37
3х+28-2х=37
х=37-28
х=9
у=14-х
у=14-9
у=5  
Ответ: стульев с тремя ножками было 9, с двумя ножками 5 

Answer 2

Solving the Problem

To solve this problem, we need to find out how many chairs with three legs were brought into the workshop. We are given that 28 chairs were brought in total, some with one leg, some with two legs, and some with three legs. The total number of legs counted was 51. We also know that the number of chairs with one leg is the same as the number of chairs with two legs.

Let's denote: - x as the number of chairs with one leg - y as the number of chairs with two legs - z as the number of chairs with three legs

We can form the following equations based on the given information: 1. x + y + z = 28 (total number of chairs) 2. x + 2y + 3z = 51 (total number of legs)

We also know that x = y.

Let's solve these equations to find the values of x, y, and z.

Solution

Using the given equations, we can solve for the values of x, y, and z:

From the equation x + y + z = 28, we know that x = y. So, we can rewrite the equation as: 2x + z = 28

From the equation x + 2y + 3z = 51, substituting x = y, we get: 3x + 3z = 51 x + z = 17

Now we have a system of equations: 2x + z = 28 x + z = 17

Subtracting the second equation from the first, we get: x = 11

Substituting x = 11 into x + z = 17, we find: 11 + z = 17 z = 6

So, the number of chairs with three legs is 6.

Conclusion

Therefore, the number of chairs with three legs brought into the workshop is 6.