Question

Книги стоят на трех полках:  На верхней полке - всего 1 книга  На средней полке столько книг, сколько на двух других вместе  Если к книге с верхней полки добавить половину книг со средней полки, то получится количество книг на нижней полке.

Answer 1

Если взять количество книг на нижней полке за «х» то на средней будет «1+х» книг. 
1+(1+х)/2=х (домножим обе части на два)
2+1+х=2х
х=3 книг на нижней  полке, следовательно на средней полке 1+х=1+3=4 книги

Answer 2

Problem Analysis

We are given the following information about the number of books on three shelves: - The top shelf has only 1 book. - The middle shelf has as many books as the other two shelves combined. - If we add half of the books from the middle shelf to the book on the top shelf, we will get the number of books on the bottom shelf.

We need to determine the number of books on each shelf.

Solution

Let's assume the number of books on the top shelf is x. According to the given information, the number of books on the middle shelf is x + 2x = 3x. If we add half of the books from the middle shelf to the book on the top shelf, we get x + (1/2)(3x) = x + (3/2)x = (5/2)x books. This number is equal to the number of books on the bottom shelf.

To find the value of x, we can set up the equation: (5/2)x = x + (3/2)x

Simplifying the equation: (5/2)x - (3/2)x = x (2/2)x = x x = 1

Therefore, there is 1 book on the top shelf, 3 books on the middle shelf, and 5 books on the bottom shelf.

Answer

There is 1 book on the top shelf, 3 books on the middle shelf, and 5 books on the bottom shelf.