Question

Решите задачу алгебраическим способом. Оля, Катя и Маша собирали ракушки на берегу моря. Катя собрала на 7 ракушек больше чем Оля, а а Маша собрала на 3 ракушки меньше чем Оля. Сколько ракушек собрала Маша, если всего девочки собрали 25 ракушек? С полным решением, пожалуйста!

Answer 1

Х - Оля х+7 - Катя х-3 - Маша х+х+7+х-3=25 3х=21 х=7 7-3=4 ракушки Маша

Answer 2

Problem Analysis

We are given that Katya collected 7 more seashells than Olya, and Masha collected 3 fewer seashells than Olya. The total number of seashells collected by the three girls is 25. We need to find out how many seashells Masha collected.

Solution

Let's assume that Olya collected x seashells. According to the problem, Katya collected 7 more seashells than Olya, so Katya collected (x + 7) seashells. Masha collected 3 fewer seashells than Olya, so Masha collected (x - 3) seashells.

The total number of seashells collected by the three girls is 25, so we can write the equation:

x + (x + 7) + (x - 3) = 25

Simplifying the equation:

3x + 4 = 25

Subtracting 4 from both sides:

3x = 21

Dividing both sides by 3:

x = 7

Therefore, Olya collected 7 seashells, Katya collected (7 + 7) = 14 seashells, and Masha collected (7 - 3) = 4 seashells.

Answer

Masha collected 4 seashells.

Explanation

According to the problem, Olya collected 7 seashells, Katya collected 14 seashells, and Masha collected 4 seashells. This satisfies the conditions given in the problem, and the total number of seashells collected by the three girls is 25.