Question

За 3 корочки хлеба и 2 кружки молока надо заплатить 20 монет.сколько стоит одна корочка хлеба,если она дешевле одной кружки молока на 5 монет?

Answer 1

1) 3(х-5)+2х=20
3х-15+2х=20
3х+2х=20+15
5х=35
х=35:5
х=7(руб) - кружка молока.
2) 7-5=2(руб.) - корка хлеба.
Ответ: 2 рубля.

Answer 2

Calculation of the Cost

To calculate the cost of one loaf of bread, we can set up the following equation:

3 * (cost of one loaf of bread) + 2 * (cost of one mug of milk) = 20

Let's assume the cost of one loaf of bread is x and the cost of one mug of milk is y.

Therefore, the equation becomes:

3x + 2y = 20

We also know that the loaf of bread is cheaper than one mug of milk by 5 coins. So, we can set up another equation:

x = y - 5

Now we have a system of two equations:

3x + 2y = 20 x = y - 5

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

From the second equation, we can express x in terms of y:

x = y - 5

Substituting this value of x into the first equation:

3(y - 5) + 2y = 20

Simplifying the equation:

3y - 15 + 2y = 20 5y - 15 = 20 5y = 35 y = 7

Now that we have the value of y, we can substitute it back into the second equation to find the value of x:

x = y - 5 x = 7 - 5 x = 2

Therefore, one loaf of bread costs 2 coins.

Conclusion

Based on the given information, one loaf of bread costs 2 coins.