Question

Ученик загадал число, увеличил его в 1 5 раз, прибавил 2,3 и получил 7,8. Какое число он задумал? - 6

Answer 1

Обозначим задуманнное число -Х
значит Х*15+2,3=7,8

15х=7,8-2,3
15х=5,5
х=5,5/15
х=0,366666666666
или где то в условии ошибка

Answer 2

Problem Analysis

The student has chosen a number, multiplied it by 5, added 2.3, and obtained a result of 7.8. We need to determine the original number the student had in mind.

Solution

Let's assume the original number the student had in mind is represented by the variable x.

According to the problem statement, the student multiplied the number by 5, added 2.3, and obtained a result of 7.8. We can represent this information in the form of an equation:

5x + 2.3 = 7.8

To find the value of x, we need to isolate it on one side of the equation. We can do this by subtracting 2.3 from both sides of the equation:

5x = 7.8 - 2.3

Simplifying the right side of the equation:

5x = 5.5

Finally, we can solve for x by dividing both sides of the equation by 5:

x = 5.5 / 5

Evaluating the expression:

x = 1.1

Therefore, the number the student had in mind is 1.1.

Answer

The number the student had in mind is 1.1.