Question

Всех кни 1157. На трех полках стоят книги. На первой полке 1 4 на второй полке 40% всех книг, а на третьей полке 28 кни Сколько всего книг находится на трех полках? ​

Answer 1

Ответ:

Пошаговое объяснение:
40% = 40/1 00 = 2/5

Все книги = х
1 полка = 1/4х книг
2 полка = 2/5х книг
3 полка = 28 книг

1/4х + 2/5х + 28 = х
5/20х + 8/20х + 28 = х
13/20х + 28 = х
13/20х - х = -28
-7/20х = -28
х = -28 : (-7/20)
х = -28 * (-20/7)
х = -4 * (-20/1)
х = 80/1
х = 80

Все книги = (х) = 80 штук

Ответ: 80 книг

Answer 2

Calculating the Total Number of Books on Three Shelves

To calculate the total number of books on the three shelves, we can use the information provided.

Let's denote: - The number of books on the first shelf as x - The number of books on the second shelf as 40% of x - The number of books on the third shelf as 28

We can then form an equation to find the total number of books.

Solution:

The total number of books on the three shelves can be calculated using the following equation: x + 40% of x + 28 = Total number of books

Calculating the Total Number of Books:

Let's calculate the total number of books using the equation.

Given: - Number of books on the first shelf, x = 1 + 4 = 5 - Number of books on the second shelf = 40% of x - Number of books on the third shelf = 28

Using the equation: 5 + 40% of 5 + 28 = Total number of books

Calculating 40% of 5: 40% of 5 = 0.4 * 5 = 2

Substituting the values: 5 + 2 + 28 = Total number of books 35 = Total number of books

Answer:

The total number of books on the three shelves is 35.