Question

Срочно !!!!!!!!!!!!!!!!! помогите решить задачу даю 20 баллов В растворе содержится 36% соли. Если добавить 130 г соли, то в растворе будет содержаться 62% соли. Какова первоначальная масса раствора? Сколько граммов соли было в растворе первоначально?

Answer 1

Было 36 проц. соли стало 62, значит добавили 26 процентов. (это  и есть 130 г)
составим пропорцию:
26% = 130 г
100% = Х

значит Х = 100*130/26 = 500 (стало раствора)

а первоначальная масса раствора равна 500 - 130 = 370 г.

Из этих 370 гр 36% было соли. Значит снова пропорция:
370 = 100%
Х = 36%

Х = 133,2 (масса соли изначальная)

Answer 2

0,36х+130=0,62(х+130)
0,36+130=0,62х+80,6
-0,26х = -49,4
х = 190 это было раствора, а соли в нем было первоначально 0,36*190=64,8г 

вроде бы так

Answer 3

Problem Analysis

We are given that a solution initially contains 36% salt. When 130 grams of salt is added to the solution, the salt concentration increases to 62%. We need to find the initial mass of the solution and the amount of salt that was initially present.

Solution

Let's assume the initial mass of the solution is x grams and the initial mass of the salt is y grams.

According to the problem, the solution initially contains 36% salt. This means that the mass of the salt in the initial solution is 36% of the initial mass of the solution: y = 0.36x.

When 130 grams of salt is added to the solution, the salt concentration increases to 62%. This means that the mass of the salt in the final solution is 62% of the final mass of the solution, which is the sum of the initial mass of the solution and the added salt: y + 130 = 0.62(x + 130).

We can solve this system of equations to find the values of x and y.

Solving the Equations

Let's solve the system of equations using substitution.

From the first equation, we have y = 0.36x.

Substituting this value of y into the second equation, we get: 0.36x + 130 = 0.62(x + 130).

Simplifying the equation, we have: 0.36x + 130 = 0.62x + 80.6.

Rearranging the equation, we get: 0.62x - 0.36x = 130 - 80.6.

Simplifying further, we have: 0.26x = 49.4.

Dividing both sides of the equation by 0.26, we get: x = 190.

Substituting this value of x into the first equation, we can find the value of y: y = 0.36 * 190 = 68.4.

Answer

Therefore, the initial mass of the solution is 190 grams and the amount of salt that was initially present is 68.4 grams.

Please let me know if you need any further assistance!