Question

даю 25 баллов помогите пж . число книг на первой полке составляло 3/4 от числа книг на второй полке. когда со второй полки на первую переставили 3 книги то число книг на первой полке составило 4/5 от числа книг на второй полке. сколько книг стояло на двух полках первоначально

Answer 1

Ответ:

Ну смотри

Пошаговое объяснение:

1)3/4х + 3 = 4/5(х - 3)

2)3/4х + 3 = 4/5х - 12/5

3)3/4х - 4/5х = - 3 - 2 2/5

4)-1/20х = -5 2/5

5)х = -27/5 : (-1/20)

6)х = -27/5 * (-20)

х = 108 книг стояло на второй полке первоначально

108*3/4 = 81 книга стояли на первой полке первоначально!!!

Answer 2

Problem Analysis

We are given information about the number of books on two shelves. Initially, the number of books on the first shelf is 3/4 of the number of books on the second shelf. After moving 3 books from the second shelf to the first shelf, the number of books on the first shelf becomes 4/5 of the number of books on the second shelf. We need to determine the initial number of books on both shelves.

Solution

Let's assume the initial number of books on the second shelf is x. According to the given information, the number of books on the first shelf is 3/4 of x.

After moving 3 books from the second shelf to the first shelf, the number of books on the first shelf becomes 4/5 of the number of books on the second shelf. This can be expressed as:

(3/4)x + 3 = (4/5)x

To solve this equation, we can multiply both sides by 20 to eliminate the fractions:

20 * (3/4)x + 20 * 3 = 20 * (4/5)x

15x + 60 = 16x

Rearranging the equation:

16x - 15x = 60

x = 60

Therefore, the initial number of books on the second shelf is 60. Since the number of books on the first shelf is 3/4 of the number of books on the second shelf, the initial number of books on the first shelf is:

(3/4) * 60 = 45

So, initially, there were 45 books on the first shelf and 60 books on the second shelf.

Answer: The initial number of books on the first shelf was 45, and the initial number of books on the second shelf was 60.