Question

Задача:тетрадь и блокнот стоят вместе 80 рублей, блокнот и карандаш вместе стоят 60 рублей , тетрадь и карандаш вместе стоят 64 рубля. Сколько стои каждый предмет в отдельности?

Answer 1

пусть х - стоимость тетради

у- стоимость блокнота

а- стоимость карандаша

 

х+у=80   х=80-у

у+а=60   а=60-у

х+а=64   80-у+60-у=64

              2у=76

              у=38

х=80-38=42

а=60-38=22

Ответ: тетрадь стоит 42р, блокнот стоит 38р, карандаш стоит 22р

 

 

 

Answer 2

Task: Finding the individual prices of each item

To find the individual prices of each item, we can set up a system of equations based on the given information.

Let's assign variables to each item: - Let's call the price of the notebook "N" - Let's call the price of the notepad "T" - Let's call the price of the pencil "P"

We have the following information: 1. The notebook and notepad together cost 80 rubles: N + T = 80. 2. The notebook and pencil together cost 60 rubles: N + P = 60. 3. The notepad and pencil together cost 64 rubles: T + P = 64.

To solve this system of equations, we can use substitution or elimination methods. Let's use the elimination method:

1. Multiply equation 1 by -1: -N - T = -80. 2. Add equation 2 to equation 1: -N - T + N + P = -80 + 60. This simplifies to: P - T = -20.

Now we have two equations: - Equation 3: T + P = 64 - Equation 4: P - T = -20

Adding equations 3 and 4 eliminates the variable "T": T + P + P - T = 64 - 20 This simplifies to: 2P = 44

Dividing both sides of the equation by 2, we find that P = 22.

Now we can substitute the value of P back into one of the original equations to find the value of T: Using equation 3: T + 22 = 64 This simplifies to: T = 42.

Finally, we can substitute the values of P and T into one of the original equations to find the value of N: Using equation 1: N + 42 = 80 This simplifies to: N = 38.

Therefore, the individual prices of each item are: - The notebook costs 38 rubles - The notepad costs 42 rubles - The pencil costs 22 rubles.

Please note that these calculations are based on the given information and the assumption that the prices of the items are in rubles.

Let me know if there's anything else I can help you with!