Question

Тетрадь, ручка, карандаш и журнал стоят 39 рублей.Тетрадь, ручка и карандаш стоят 18 рублей.Журнал ручка и карандаш сточт 35 рублей.Тетрадь и карандаш стоят 7 рублей.Сколько стоит каждая вещь?

Answer 1

1)39-18=21(руб.)-стоит журнал
2)35-21=14(руб.)-стоят ручка и карандаш
3)18-14=4(руб.)-стоит тетрадь
4)7-4=3(руб.)-стоит карандаш
5)35-(21+3)=11(руб.)-стоит ручка
Ответ:журнал стоит 21 рубль,тетрадь стоит 4 рубля,карандаш стоит 3 рубля,ручка стоит 11 рублей.

Answer 2

Problem Analysis

We are given the prices of different items and their combinations. We need to determine the individual prices of each item.

Solution

Let's assign variables to the prices of the items: - Let the price of the notebook (тетрадь) be N rubles. - Let the price of the pen (ручка) be P rubles. - Let the price of the pencil (карандаш) be C rubles. - Let the price of the magazine (журнал) be M rubles.

From the given information, we can form the following equations:

Equation 1: N + P + C + M = 39 (The total price of all items is 39 rubles) Equation 2: N + P + C = 18 (The price of the notebook, pen, and pencil is 18 rubles) Equation 3: P + C + M = 35 (The price of the pen, pencil, and magazine is 35 rubles) Equation 4: N + C = 7 (The price of the notebook and pencil is 7 rubles)

To solve these equations, we can use substitution or elimination method. Let's use the elimination method.

Subtracting Equation 4 from Equation 2, we get: (N + P + C) - (N + C) = 18 - 7 P = 11

Subtracting Equation 4 from Equation 3, we get: (P + C + M) - (N + C) = 35 - 7 P + M - N = 28

Substituting the value of P from Equation 2 into the above equation, we get: 11 + M - N = 28 M - N = 17

Now, we have two equations: P = 11 (Equation 5) M - N = 17 (Equation 6)

From Equation 5, we know that the price of the pen is 11 rubles.

Substituting the value of P into Equation 2, we get: N + 11 + C = 18 N + C = 7

From Equation 4, we know that the price of the notebook and pencil is 7 rubles.

Now, we can solve Equation 6 to find the value of M: M - N = 17 M = N + 17

Substituting the value of M into Equation 3, we get: 11 + C + (N + 17) = 35 C + N = 7

From Equation 4, we know that the price of the notebook and pencil is 7 rubles.

Now, we have two equations: N + C = 7 (Equation 7) C + N = 7 (Equation 8)

Adding Equation 7 and Equation 8, we get: 2N + 2C = 14 N + C = 7

Subtracting Equation 8 from Equation 7, we get: N - C = 0

Adding Equation 7 and Equation 8, we get: 2N = 7 N = 3.5

Substituting the value of N into Equation 8, we get: 3.5 + C = 7 C = 3.5

Therefore, the price of the notebook (тетрадь) is 3.5 rubles, the price of the pen (ручка) is 11 rubles, the price of the pencil (карандаш) is 3.5 rubles, and the price of the magazine (журнал) is 20.5 rubles.

Answer

Based on the given information, the prices of each item are as follows: - The notebook (тетрадь) costs 3.5 rubles. - The pen (ручка) costs 11 rubles. - The pencil (карандаш) costs 3.5 rubles. - The magazine (журнал) costs 20.5 rubles.

Please note that the source provided does not contain the specific information required to solve this problem.