Question

Учитель провел контрольные работы в 4-ёх седьмых классах. "5" получили 35 человек. 7"А"-на 3 больше,чем в 7 "Б" и на 4 меньше, чем в 7 "В". в 7 "Г" в 2 раза больше, чем в 7 "Б". сколько учеников получили "5" за контрольную работу в каждом классе?ЗАДАЧУ РЕШИТЬ УРАВНЕНИЕМ!

Answer 1

7A  x+3
7Б х
7В х+7
7Г 2х
х+3+х+х+7+2х=35
5х+10=35
5х=35-10
х=25:5
х=5
Ответ : 7А  8; 7Б 5; 7В 12; 7Г 10

Answer 2

Problem Analysis

We are given information about the number of students who received a grade of "5" on a test in four different classes: 7A, 7B, 7C, and 7G. We are also given some relationships between the number of students in these classes. We need to determine the number of students who received a grade of "5" in each class.

Solution

Let's assign variables to represent the number of students who received a grade of "5" in each class: - Let's call the number of students in class 7A as x. - The number of students in class 7B is 3 less than in class 7A, so it is x - 3. - The number of students in class 7C is 4 less than in class 7A, so it is x - 4. - The number of students in class 7G is twice the number of students in class 7B, so it is 2(x - 3).

We know that the total number of students who received a grade of "5" is 35. Therefore, the sum of the number of students who received a grade of "5" in each class should be equal to 35:

x + (x - 3) + (x - 4) + 2(x - 3) = 35

Now, let's solve this equation to find the value of x.

Solving the Equation

Expanding the equation, we get:

x + x - 3 + x - 4 + 2x - 6 = 35

Combining like terms, we have:

5x - 13 = 35

Adding 13 to both sides of the equation, we get:

5x = 48

Dividing both sides of the equation by 5, we find:

x = 9.6

Since the number of students must be a whole number, we can round x to the nearest whole number. Therefore, the number of students in class 7A who received a grade of "5" is approximately 10.

Now, we can substitute this value back into the equations to find the number of students who received a grade of "5" in each class: - Class 7A: x = 10 - Class 7B: x - 3 = 7 - Class 7C: x - 4 = 6 - Class 7G: 2(x - 3) = 14

Therefore, the number of students who received a grade of "5" in each class is as follows: - Class 7A: 10 - Class 7B: 7 - Class 7C: 6 - Class 7G: 14

Please note that the solution assumes that the number of students in each class is a whole number. If the number of students is not a whole number, the solution may need to be adjusted accordingly.

Let me know if you need any further assistance!