Question

Помогите решить задачу !!! На вопрос о том,сколько лет ему и его брату ,Федор ответил: "Вместе нам 20 лет , а 4 года назад я был в 2 раза старше брата,сосчитайте , сколько лет каждому из нас ".

Answer 1

Узнаем сколько им было лет вместе 4 года назад.
Для этого вычтем из 20 два раза по 4 за Федора и за брата
20 - 8 = 12

Отсюда логически Федору было 8 лет, а брату 4 года тогда.
Или уравнением : х-брату, 2х-Федору
2х + х =12
3х=12
х=4 (года было брату) 2 х 4 = 8 (лет было Федору)

Теперь узнаем сколько лет теперь Федору и брату
4+4=8 (лет брату сейчас)
8+4=12 (лет Федору сейчас)

Answer 2

Problem Analysis

The problem states that the sum of the ages of Fedor and his brother is 20 years, and four years ago, Fedor was twice as old as his brother. We need to calculate the ages of both Fedor and his brother.

Solution

Let's assume Fedor's age is represented by F and his brother's age is represented by B.

According to the problem, the sum of their ages is 20 years: F + B = 20. Four years ago, Fedor was twice as old as his brother: F - 4 = 2(B - 4). We can solve this system of equations to find the values of F and B.

Solving the System of Equations

We can start by simplifying the second equation: F - 4 = 2B - 8.

Next, we can rearrange the equation to isolate F: F = 2B - 4.

Now, we substitute this expression for F into the first equation: (2B - 4) + B = 20.

Simplifying further: 3B - 4 = 20.

Adding 4 to both sides of the equation: 3B = 24.

Dividing both sides by 3: B = 8.

Now that we have the value of B, we can substitute it back into the first equation to find F: F + 8 = 20.

Subtracting 8 from both sides of the equation: F = 12.

Therefore, Fedor is 12 years old and his brother is 8 years old.

Answer

Fedor is 12 years old and his brother is 8 years old.