Question

За 2 футбольных и 4 волейбольных мяча заплатили 20000 рублей. После того как футбольный мяч подешевел на 20%, а волейбольный подорожал на 10%, за один футбольный и один волейбольный мячи заплатили 6500 рублей. Какова первоначальная цена каждого мяча? вопросы:1.Первоначальная цена футбольного мяча.2.Первоначальная цена волейбольного мяча.СРОЧНО ПОМОГИТЕ!

Answer 1

Ответ:

Объяснение: фото

Answer 2

Ответ:

2 х+4 у=20001,2 х+0,9 у=650

х+2 у=10001,2 х+0,9 у=650 х=1000-2 у

1,2 (1000-2 у) + 0,9 у=6501200-2,4 у+0,9 у=6501,5 у=550 у=366,67

х=1000-2*366,67=266,67

Ответ: 267 рублей

Answer 3

Problem Analysis

We are given the information that 2 footballs and 4 volleyballs were purchased for a total of 20,000 rubles. After the price of the football decreased by 20% and the price of the volleyball increased by 10%, one football and one volleyball were purchased for a total of 6,500 rubles. We need to find the initial price of each ball.

Solution

Let's assume the initial price of a football is x rubles and the initial price of a volleyball is y rubles.

From the given information, we can form the following equations:

Equation 1: 2x + 4y = 20,000 (total cost of 2 footballs and 4 volleyballs is 20,000 rubles)

Equation 2: (0.8x) + (1.1y) = 6,500 (cost of 1 football after a 20% decrease and 1 volleyball after a 10% increase is 6,500 rubles)

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

From Equation 1, we can express x in terms of y:

2x = 20,000 - 4y x = (20,000 - 4y)/2 x = 10,000 - 2y

Substituting this value of x into Equation 2:

0.8(10,000 - 2y) + 1.1y = 6,500 8,000 - 1.6y + 1.1y = 6,500 -0.5y = -1,500 y = 3,000

Now that we have the value of y, we can substitute it back into Equation 1 to find the value of x:

2x + 4(3,000) = 20,000 2x + 12,000 = 20,000 2x = 8,000 x = 4,000

Therefore, the initial price of each football ball was 4,000 rubles and the initial price of each volleyball ball was 3,000 rubles.

Answer

1. The initial price of the football ball was 4,000 rubles. 2. The initial price of the volleyball ball was 3,000 rubles.