Question

НА ВТОРОЙ ПОЛКЕ СТОЯЛО В 3 РАЗА БОЛЬШЕ КНИГ,ЧЕМ НА ПЕРВОЙ . ПОСЛЕ ТОГО,КАК СО ВТОРОЙ ПОЛКИ ПЕРЕСТАВИЛИ 10 КНИГ НА ПЕРВУЮ,НА ОБЕИХ ПОЛКАХ КНИГ СТАЛО ПОРОВНУ. НА ПЕРВОЙ ПОЛКЕ БЫЛО _____КНИГ

Answer 1

Х-на 1й

х+10=3х-10
х-3х=-10-10
-2х=-20
2х=20
х=20/2
х=10

Answer 2

Пусть х книг было на первой полке, тогда (3х) книг было на второй полке. (х+10) книг стало на первой полке, (3х-10) книг стало на второй полке.
Составим и решим уравнение
х+10 = 3х-10
х-3х = -10-10
-2х = -20 
2х = 20
х=10
1) Значит, 10 книг было на первой полке
2) 3*10 = 30 (книг) было на второй
Ответ: 10 книг 

Answer 3

Problem Analysis

Let's break down the information provided in the question:

- On the second shelf, there were 3 times more books than on the first shelf. - After moving 10 books from the second shelf to the first shelf, the number of books became equal on both shelves.

We need to determine the number of books on the first shelf before the 10 books were moved.

Solution

Let's assume the number of books on the first shelf is represented by x. According to the information given, the number of books on the second shelf is 3 times more than the number on the first shelf, which can be represented as 3x.

After moving 10 books from the second shelf to the first shelf, the number of books on both shelves becomes equal. This can be expressed as:

**x + 10 = 3