Question

Купили тетради,книгу и альбом.Стоимость тетрадей составляет 0,3 стоимости книги; альбом на 50 руб дешевле книги,Скольео заплатили за тетради,если книга и альбом вместе стоят 180 рублей?

Answer 1

Пусть 0,3х - стоимость тетради, тогда х - 50 - стоимость альбома, а х - стоимость книги. Если книга и альбом: х+(х-50)=180, то:
2х=180+50
2х=230
х=230:2
х=115
115 - стоит книга
1).115-50=65 - стоит альбом
2). 115 * 0,3= 34,5 - стоит тетрадь.
Ответ: 115руб., 65руб., 34,5руб.

Answer 2

Problem Analysis

We are given the following information: - The cost of the notebooks is 0.3 times the cost of the book. - The album is 50 rubles cheaper than the book. - The total cost of the book and the album is 180 rubles.

We need to find the cost of the notebooks.

Solution

Let's assume the cost of the book is x rubles.

According to the given information: - The cost of the notebooks is 0.3 times the cost of the book, so the cost of the notebooks is 0.3x rubles. - The album is 50 rubles cheaper than the book, so the cost of the album is (x - 50) rubles. - The total cost of the book and the album is 180 rubles, so we have the equation: x + (x - 50) = 180.

Now, let's solve the equation to find the value of x and then calculate the cost of the notebooks.

Calculation

x + (x - 50) = 180

Combining like terms: 2x - 50 = 180

Adding 50 to both sides: 2x = 230

Dividing both sides by 2: x = 115

The cost of the book is 115 rubles.

Now, let's calculate the cost of the notebooks: Cost of the notebooks = 0.3 * x = 0.3 * 115 = 34.5 rubles.

Answer

The cost of the notebooks is 34.5 rubles.