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:
0.4077
Step-by-step explanation:
It's important to use parenthesis to avoid confusion.
9^(2x) = 6
Use exponent properties:
(9^2)^x = 6
81^x = 6
Take log of both sides
ln(81^x) = ln(6)
Use log properties:
x ln(81) = ln(6)
Solve for x:
x = ln(6) / ln(81)
x ≈ 0.4077
Answer:
2) x=60
Step-by-step explanation:
x/6=10
multiply both sides by 6
x = 10*6
x=60
hope this helps! :D
have a miraculous day!! <3
Answer:
D)
Step-by-step explanation:
f(x) = x^2 -14x -72
0=x^2 - 14x-72
0=x^2 - 18x+4x-72
0=x(x-18)+4(x-18)
0=(x-18)(x+4)
x-18=0 or x+4=0
x1=18 or x2=-4
asis of symmetry: x=(x1+x2)/2
x=(18+(-4))/2
x=14/2
x=7
Let the original number be x
X^2 + 11 = 36
Subtract 11
X^2 = 25
Square root both
X = 5
Solution: her original number is 5
