Question

K X г 25%-го раствора добавили 140 г 7%-ый раствор, при этом образовался 32%- ый раствор. Определите значение У. если значение Х в 4 раза больше значения У.​

Answer 1

Ответ:

-125

Объяснение:

Давайте решим эту задачу. Пусть значение У равно У грамм. Тогда значение Х будет равно 4У грамм.

По условию задачи, мы имеем 25%-й раствор, в котором добавляем 140 г 7%-го раствора. После смешивания получаем 32%-й раствор.

Давайте выразим это математически. Общая масса раствора равна сумме массы первого и второго растворов:

25% * Х + 7% * 140 г = 32% * (Х + 140 г)

Переведем проценты в десятичные дроби:

0.25 * 4У + 0.07 * 140 г = 0.32 * (4У + 140 г)

Упростим выражение:

У + 9.8 г = 1.28У + 44.8 г

Вычтем У из обеих частей уравнения:

9.8 г = 0.28У + 44.8 г

Вычтем 0.28У из обеих частей уравнения:

9.8 г - 44.8 г = 0.28У

-35 г = 0.28У

Разделим обе части на 0.28:

У = -35 г / 0.28

У ≈ -125 г

Таким образом, значение У примерно равно -125 г.

Answer 2

Problem Analysis

We are given that 140 grams of a 7% solution is added to a solution of KX that is 25% concentration. As a result, a 32% solution is formed. We need to determine the value of Y, given that the value of X is 4 times greater than the value of Y.

Solution

Let's assume the initial volume of the 25% KX solution is V1 and the initial concentration of KX is C1. The amount of KX in the initial solution is then V1 * C1.

We are also given that 140 grams of a 7% solution is added. This means that the amount of KX in the 7% solution is 140 * 0.07 = 9.8 grams.

After mixing the two solutions, the resulting volume is V1 + 140 grams. The concentration of the resulting solution is 32%.

We can set up the following equation to solve for V1:

(V1 * C1 + 9.8 grams) / (V1 + 140 grams) = 0.32

Simplifying the equation, we get:

V1 * C1 + 9.8 grams = 0.32 * (V1 + 140 grams) V1 * C1 + 9.8 grams = 0.32 * V1 + 0.32 * 140 grams V1 * (C1 - 0.32) = 0.32 * 140 grams - 9.8 grams V1 = (0.32 * 140 grams - 9.8 grams) / (C1 - 0.32)

Now, we are given that the value of X is 4 times greater than the value of Y. Let's assume the value of Y is Y grams. Therefore, the value of X is 4Y grams.

We can set up the following equation to solve for Y:

X = 4Y V1 * C1 = 4Y

Substituting the value of V1 from the previous equation, we get:

((0.32 * 140 grams - 9.8 grams) / (C1 - 0.32)) * C1 = 4Y

Simplifying the equation, we get:

((0.32 * 140 grams - 9.8 grams) * C1) / (C1 - 0.32) = 4Y ((0.32 * 140 grams - 9.8 grams) * C1) = 4Y * (C1 - 0.32) ((0.32 * 140 grams - 9.8 grams) * C1) = 4Y * C1 - 4Y * 0.32 ((0.32 * 140 grams - 9.8 grams) * C1) - 4Y * C1 = - 4Y * 0.32 ((0.32 * 140 grams - 9.8 grams) - 4Y) * C1 = - 4Y * 0.32 ((0.32 * 140 grams - 9.8 grams) - 4Y) = (- 4Y * 0.32) / C1 (0.32 * 140 grams - 9.8 grams) - 4Y = (- 4Y * 0.32) / C1 (0.32 * 140 grams - 9.8 grams) = (- 4Y * 0.32) / C1 + 4Y (0.32 * 140 grams - 9.8 grams) = 4Y * (1 - 0.32 / C1) Y = (0.32 * 140 grams - 9.8 grams) / (4 * (1 - 0.32 / C1))

Now, we need to find the value of Y. To do that, we need to know the value of C1, the initial concentration of the KX solution. Unfortunately, we don't have that information available. Without the value of C1, we cannot determine the value of Y.

Therefore, we cannot determine the value of Y based on the given information.

Conclusion

Based on the given information, we cannot determine the value of Y. The value of Y depends on the initial concentration of the KX solution, which is not provided.