Question

Четыре арбуза и три ананаса весят 15 кг, а три арбуза и четыре ананаса весят 13 кг. Сколько килограммов весят арбуз и ананас в отдельности?

Answer 1

За арбуз возьмём х
За ананас возьмём у
Составим систему:
4х+3у=15
3х+4у=13

16х+12у=60 (умножили обе части на 4)
-9х-12у=-39 (умножили обе части на -3)
———————
7х=21 (сложили уравнения)
х=21:7
х=3
Теперь найдём у. Для этого х подставим:
3*3+4у=13
9+4у=13
4у=13-9
4у=4
у=4:4
у=1

Ответ. Арбуз х= 3, ананас у = 1.
Арбуз 3кг, ананас 1 кг

Answer 2

Calculation of the Weight of Watermelon and Pineapple Separately

To solve this problem, we can set up a system of equations based on the given information.

Let's assume that the weight of one watermelon is represented by w and the weight of one pineapple is represented by p.

According to the given information, we have two equations:

Equation 1: 4w + 3p = 15 (Four watermelons and three pineapples weigh 15 kg)

Equation 2: 3w + 4p = 13 (Three watermelons and four pineapples weigh 13 kg)

To find the weight of the watermelon and pineapple separately, we can solve this system of equations.

Solving the System of Equations

We can solve this system of equations using various methods, such as substitution or elimination. Let's use the elimination method to solve this system.

Multiplying Equation 1 by 3 and Equation 2 by 4, we get:

Equation 3: 12w + 9p = 45

Equation 4: 12w + 16p = 52

Now, subtracting Equation 3 from Equation 4, we can eliminate the variable w:

(12w + 16p) - (12w + 9p) = 52 - 45

Simplifying the equation, we have:

7p = 7

Dividing both sides of the equation by 7, we find:

p = 1

Now that we have the weight of one pineapple, we can substitute this value into Equation 1 to find the weight of one watermelon:

4w + 3(1) = 15

Simplifying the equation, we have:

4w + 3 = 15

Subtracting 3 from both sides of the equation, we get:

4w = 12

Dividing both sides of the equation by 4, we find:

w = 3

Answer

Therefore, the weight of one watermelon is 3 kg and the weight of one pineapple is 1 kg.

Please let me know if there is anything else I can help you with!