Question

на первой полке было в 5 раз больше книг,чем на второй.Когда с первой полки взяли 12 книг,а на вторую добавили 8 книг,то количество книг стало одинаковым.Сколько книг было на первой полке?

Answer 1

Ответ:

x=5y

x-12=y+8

5y-12=y+8

4y=20

y=5

x=25

Answer 2

Solution:

Let's solve the problem step by step.

1. Let's assume the number of books on the second shelf is x. 2. According to the given information, the number of books on the first shelf is 5 times more than the number of books on the second shelf, so it is 5x. 3. When 12 books are taken from the first shelf and 8 books are added to the second shelf, the number of books becomes equal on both shelves.

Now, we can create an equation to solve for x.

The equation can be formed as: 5x - 12 = x + 8

Let's solve for x.

5x - 12 = x + 8

5x - x = 8 + 12

4x = 20

x = 5

So, the number of books on the second shelf is 5.

Now, to find the number of books on the first shelf, we can use the fact that it is 5 times the number of books on the second shelf.

5x = 5 * 5 = 25

Answer:

The number of books on the first shelf was 25.