Question

Три ватрушки и пять плюшек стоят 45р а пять ватрушек и три плюшки Стоят 43р сколько стоит ватруша и плюшка И МОЖНО СИСТЕМОЙ УРАВНЕНИЙ!

Answer 1

Ватрушка - x
Плюшка - y

3x+5y=45 
5x+3y=43

первое уравнение умножаем на 5
второе уравнение умножаем на 3

15x+25y=225
15x+9y=129

выражаем через первое уравнение 15x
15x=225-25y
подставляем это во второе уравнение 
получаем
225-25y+9y=129
16y=96
y=6
подставляем в первое уравнение 

15x=75
x=5

ватрушка - 5
плюшка - 6

Answer 2

Problem Analysis

We are given two equations: 1. Three vatrushki and five plyushki cost 45 rubles. 2. Five vatrushki and three plyushki cost 43 rubles.

We need to find the cost of one vatrushka and one plyushka.

Solution

Let's assume the cost of one vatrushka is 'x' rubles and the cost of one plyushka is 'y' rubles.

According to the given information, we can form the following equations:

Equation 1: 3x + 5y = 45 (Three vatrushki and five plyushki cost 45 rubles) Equation 2: 5x + 3y = 43 (Five vatrushki and three plyushki cost 43 rubles)

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

Let's solve it using the method of substitution:

From Equation 1, we can express 'x' in terms of 'y': x = (45 - 5y) / 3

Substituting this value of 'x' in Equation 2, we get: 5((45 - 5y) / 3) + 3y = 43

Simplifying the equation: (225 - 25y) / 3 + 3y = 43 225 - 25y + 9y = 129 -16y = -96 y = 6

Now, substituting the value of 'y' in Equation 1, we get: 3x + 5(6) = 45 3x + 30 = 45 3x = 15 x = 5

Therefore, the cost of one vatrushka is 5 rubles and the cost of one plyushka is 6 rubles.

Conclusion

The cost of one vatrushka is 5 rubles and the cost of one plyushka is 6 rubles.