Suppose you add x liters of pure water to the 10 L of 25% acid solution. The new solution's volume is x + 10 L. Each L of pure water contributes no acid, while the starting solution contains 2.5 L of acid. So in the new solution, you end up with a concentration of (2.5 L)/(x + 10 L), and you want this concentration to be 10%. So we have
and so you would need to add 15 L of pure water to get the desired concentration of acid.
Answer:
This a circle centered at the point , and of radius "3" as it is shown in the attached image.
Step-by-step explanation:
Recall that the standard formula for a circle of radius "R", and centered at the point is given by:
Therefore, in our case, by looking at the standard equation they give us, we extract the following info:
1) since the radius must be a positive number and (
) is not a viable answer.
2) for (
) to equal
3) for (
) to equal
Therefore, we are in the presence of a circle centered at the point , and of radius "3". That is what we draw as seen in the attached image.
