Question

Масса четырех одинаковых по массе кошек и трех одинаковых котят 15кг. Если одну кошку заменить одним котенком, то масса станет 13кг. Найди массу одного котенка и одной кошки.

Answer 1

Пусть маса кошки=х,маса котенка=у.

4х+3у=15кг

3х+4у=13кг

(4х+3у)-(3х+4у)=15-13

х-у=2 или х=2+у,подставляем в уравнение 4х+3у=15,  7у+8=15,  7у=7,  у=1,х=2+у, х=2+1=3

Маса кошки:3кг,маса котенка:1кг.

Answer 2

a-кошка

b-котёнок

4a+3b=15

3a+4b=13

4a+3b+3a+4b=15+13

7a+7b=28

a+b=4-кошка и котёнок

15-3*4=3-1 кошка

13-3*4=1-1 котёнок

 

 

Answer 3

Problem Analysis

We are given that the total mass of four identical cats and three identical kittens is 15 kg. If we replace one cat with one kitten, the total mass becomes 13 kg. We need to find the mass of one kitten and one cat.

Solution

Let's assume the mass of one cat is C kg and the mass of one kitten is K kg.

According to the given information, we have the following equations:

Equation 1: 4C + 3K = 15 (total mass of cats and kittens is 15 kg) Equation 2: 3C + 4K = 13 (total mass after replacing one cat with one kitten is 13 kg)

To solve these equations, we can use the method of substitution or elimination.

Method of Substitution

We can solve the equations by isolating one variable in terms of the other and substituting it into the other equation.

From Equation 1, we can isolate C: 4C = 15 - 3K C = (15 - 3K) / 4

Substituting this value of C into Equation 2: 3((15 - 3K) / 4) + 4K = 13 (45 - 9K) / 4 + 4K = 13 45 - 9K + 16K = 52 7K = 7 K = 1

Now, substituting the value of K back into Equation 1: 4C + 3(1) = 15 4C + 3 = 15 4C = 12 C = 3

Therefore, the mass of one kitten is 1 kg and the mass of one cat is 3 kg.

Answer

The mass of one kitten is 1 kg and the mass of one cat is 3 kg.