Question

боря купил четыре книги.Все книги без первой стоят 42 рубля ,без второй 40 рублей , без третей 38 рублей , без четвёртой 36 рублей . сколько стоит каждая книга.

Answer 1

Решение:

1)42+40+38+36 = 156 – тройная стоимость всех книг

2) 156:3=52 рублей стоят все книги

3) 52-42=10 – рублей стоит первая книга

4)52-40=12 - рублей стоит вторая книга

5)52-38=14 - рублей стоит третья книга

6)52-36=16 -рублей  стот четвертая книга

Проверка:

10+12+14+16=52 рубля

Ответ: 10 рублей стоит первая книга,12 рублей стоит вторая книга,14 рублей стоит третья книга,16 рублей  стот четвертая книга.

Answer 2

Calculating the Cost of Each Book

To calculate the cost of each book, we can use the given information about the prices of the books without the first, second, third, and fourth books.

Let's denote the cost of the first book as x.

The cost of the second book is 42 rubles, so the cost of the second book is x + 2.

The cost of the third book is 40 rubles, so the cost of the third book is x + 4.

The cost of the fourth book is 38 rubles, so the cost of the fourth book is x + 6.

To find the value of x, we can set up the following equations:

1. x + 2 = 42 2. x + 4 = 40 3. x + 6 = 38

Solving these equations will give us the cost of each book.

Solution:

1. From the first equation, we get: x = 42 - 2 = 40 2. From the second equation, we get: x = 40 - 4 = 36 3. From the third equation, we get: x = 38 - 6 = 32

So, the cost of each book is: - The first book costs 40 rubles - The second book costs 42 rubles - The third book costs 36 rubles - The fourth book costs 38 rubles

This calculation is based on the given information and the equations derived from it.