Question

Выпускники одного класса решили после окончания школы обменяться фотографиями-каждый с каждым.Сколько выпускников было в классе ,если всего было роздано 930 фотографий?

Answer 1

)пусть число выпускников:х,тогда было роздано х*х-х=930 
х=31 

Answer 2

31 выпускник)
х*х-х=930
х=31
Проверка-каждый ученик (если ответ 31) раздаст по 30 фото-
930/30=31)))
ОТвет-31 выпускник)

Answer 3

Calculation of the Number of Graduates in the Class

To determine the number of graduates in the class, we can set up an equation based on the information given. Let's assume there were x graduates in the class.

According to the problem, each graduate exchanged photos with every other graduate. This means that each graduate exchanged photos with x-1 other graduates (since they wouldn't exchange photos with themselves).

Since each graduate exchanged photos with every other graduate, the total number of photo exchanges would be the sum of the number of exchanges made by each graduate. This can be calculated using the formula for the sum of the first n natural numbers: n(n-1)/2.

Therefore, the equation can be set up as follows:

x(x-1)/2 = 930

To solve this equation, we can rearrange it and solve for x:

x^2 - x - 1860 = 0

Using the quadratic formula, we can find the values of x that satisfy this equation:

x = (-b ± √(b^2 - 4ac)) / (2a)

In this case, a = 1, b = -1, and c = -1860.

Solving the equation, we find two possible solutions for x: x = 45 or x = -41. Since the number of graduates cannot be negative, we can conclude that there were 45 graduates in the class.

Answer

There were 45 graduates in the class if a total of 930 photos were exchanged.