Question

1 пирожок и 2 стакана сока стоят 38 руб. а 2 пирожка и 1 стакан сока стоит 28 руб,что дороже и НА СКОЛЬКО, пирожок или стакан сока?

Answer 1

2с.+1п.=38руб.
1с.+2п.=28руб.
1п.=38-2с.
2×(38-2с.)+1с.=28руб.
76-4с.+1с.=28
3с.=48
1с.=16руб.(цена 1 стакана сока)
1п.=38-2×16=6руб.(цена 1 пирожка)
16-6=10руб.(разница)

Answer 2

Calculation of the Cost

To determine which is more expensive, the cost of one pastry and two glasses of juice is given as 38 rubles, while the cost of two pastries and one glass of juice is given as 28 rubles.

Let's assign variables to the cost of a pastry and the cost of a glass of juice. Let's say the cost of a pastry is x rubles and the cost of a glass of juice is y rubles.

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

1 pastry + 2 glasses of juice = 38 rubles 2 pastries + 1 glass of juice = 28 rubles

We can set up a system of equations to solve for x and y:

Equation 1: x + 2y = 38 Equation 2: 2x + y = 28

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

Solving the System of Equations

Let's solve the system of equations using the method of substitution:

From Equation 2, we can express y in terms of x: y = 28 - 2x

Substituting this value of y into Equation 1: x + 2(28 - 2x) = 38 x + 56 - 4x = 38 -3x = -18 x = 6

Substituting the value of x back into Equation 2 to find y: 2(6) + y = 28 12 + y = 28 y = 16

Therefore, the cost of one pastry is 6 rubles and the cost of one glass of juice is 16 rubles.

Comparing the Costs

Now that we know the cost of a pastry and a glass of juice, we can compare their prices.

The cost of one pastry is 6 rubles, while the cost of one glass of juice is 16 rubles.

To determine which is more expensive, we can compare the prices. Since the cost of one glass of juice is higher than the cost of one pastry, we can conclude that the glass of juice is more expensive.

The difference in price between the glass of juice and the pastry is: 16 rubles - 6 rubles = 10 rubles.

Therefore, the glass of juice is more expensive than the pastry by 10 rubles.

Please note that the information provided is based on the given equations and calculations.