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:
62 i think
Step-by-step explanation:
15 is the answer it is correct can
Answer:
x = 5
y = 4
Step-by-step explanation:
1. 2x + 2y = 18
2. x + 3y = 17
Multiply the first equation by 1 and the second equation by 2 to eliminate x
We have
2x + 2y = 18
2x + 6y = 34
Subtract equation 2 from equation 1
-4y = -16
Divide both sides by -4 to isolate y
-4y/-4 = -16/-4
y = 4
Now substitute 4 for y in either equation to get x. Using equation 2 we have
x + 3y = 17
x + 3 x 4 = 17
x + 12 = 17
Subtract 12 from both sides
x + 12 - 12 = 17 - 12
x = 5
x = 5 and
y = 4
