Question

В коробке было несколько кубиков.После того как брат взял из коробки 3 кубика а сестра положила в коробку 5 кубиков в коробке стало 12 кубиков.Сколько кубиков было в коробке сначала? решить с пояснением

Answer 1

Пусть х кубиков было сначала. Тогда после того как брат взял 3 кубика их стало (х+3.); Зная, что после всех действийи в коробке стало 12 кубиков. Составим и решим ур-е:
х-3+5=12.
х=12-5+3.
х=10.
Ответ: 10 кубиков было сначала.

Answer 2

12-5=7(к) было до того как сестра положила кубики
7+3=10(к) было изначально
Ответ:10 кубиков.

Answer 3

Problem Analysis

We are given that there were several cubes in a box. After the brother took out 3 cubes and the sister put 5 cubes back into the box, there were 12 cubes in total. We need to determine how many cubes were initially in the box.

Solution

Let's assume that the initial number of cubes in the box is x.

According to the given information, the brother took out 3 cubes, so the number of cubes remaining in the box is x - 3.

Then, the sister put 5 cubes back into the box, resulting in a total of 12 cubes. Therefore, we can write the equation:

x - 3 + 5 = 12

Simplifying the equation, we have:

x + 2 = 12

Subtracting 2 from both sides of the equation, we get:

x = 10

Therefore, there were initially 10 cubes in the box.

Answer

There were initially 10 cubes in the box.

Explanation

To solve this problem, we used algebraic equations to represent the given information and find the initial number of cubes in the box. By setting up the equation x - 3 + 5 = 12, where x represents the initial number of cubes, we were able to solve for x and determine that there were 10 cubes in the box initially.