Question

Андрей и Боря вместе весят 82 кг Андрей и Витя вместе 83 кг Боря и Витя весят 85 кг.Найдите вес каждого мальчика?

Answer 1

(83-х)+(82-х)=85
получаем уравнение
83-х+82-х=85
80=2х
х=80:2
х=40 -Алеша
82-40=42 -Боря
83-40=43 -Вова

Answer 2

Finding the Weights of Each Boy

Let's denote the weights of Andrey, Borya, and Vitya as A, B, and V respectively.

We are given the following information: 1. Andrey and Borya together weigh 82 kg. 2. Andrey and Vitya together weigh 83 kg. 3. Borya and Vitya together weigh 85 kg.

We can set up a system of equations to solve for the individual weights of the boys.

Let's solve for the weights of each boy using the given information.

Equations for the Weights

We can represent the given information in the form of equations as follows:

1. A + B = 82 2. A + V = 83 3. B + V = 85

Solving the Equations

We can solve the system of equations using various methods, such as substitution or elimination. Let's use the substitution method to solve for the weights of the boys.

From equation ***, we can express A in terms of B: A = 82 - B.

Substituting this expression for A into equation ***: (82 - B) + V = 83 V = 83 - 82 + B V = 1 + B

Substituting the expression for A into equation ***: B + V = 85 B + (1 + B) = 85 (using the value of V from equation ***) 2B + 1 = 85 2B = 85 - 1 2B = 84 B = 42

Now that we have the value of B, we can find the values of A and V using the equations * and *.

From equation ***: A + 42 = 82 A = 82 - 42 A = 40

From equation ***: 40 + V = 83 V = 83 - 40 V = 43

Conclusion

Therefore, the weights of each boy are: - Andrey (A) weighs 40 kg. - Borya (B) weighs 42 kg. - Vitya (V) weighs 43 kg.