Question

помогите!!!!Игнату сейчас вчетверо больше лет, чем было его сестре в тот момент, когда она была вдвое моложе его. Сколько лет Игнату в данный момент, если через15 лет ему и сестре будет вместе 100 лет?

Answer 1

Игнату было 2х
Сестре было х
Игнату сейчас 4х
Сестре сейчас 3х
Через 15 лет будет Игнату 4х+15
Через 15 лет сестре будет 3х+15
Через 15 лет им будет 100 лет.
УРАВНЕНИЕ:
(4х+15)+(3х+15)=100
7х+30=100
7х=100-30
7х=70
х=70:7
х=10 лет сестре было тогда
4*10=40 лет Игнату

Answer 2

Problem Analysis

We are given the information that Ignat is currently four times older than his sister was when she was half his age. We are also given that in 15 years, Ignat and his sister will have a combined age of 100 years. We need to determine Ignat's current age.

Solution

Let's assume Ignat's current age is represented by I and his sister's current age is represented by S.

From the given information, we can form two equations:

1. Ignat is currently four times older than his sister was when she was half his age: - I = 4 * (S - (I/2)).

2. In 15 years, Ignat and his sister will have a combined age of 100 years: - (I + 15) + (S + 15) = 100.

We can solve these equations to find the values of I and S.

Solution Steps

1. Simplify equation 1: - I = 4S - 2I. - 3I = 4S. - I = (4/3)S.

2. Substitute the value of I in equation 2: - ((4/3)S + 15) + (S + 15) = 100. - (4/3)S + S + 30 = 100. - (7/3)S = 70. - S = (3/7) * 70. - S = 30.

3. Substitute the value of S in equation 1 to find I: - I = (4/3) * 30. - I = 40.

Therefore, Ignat is currently 40 years old.

Answer

Ignat is currently 40 years old.