SOLUTION: Write an equation in terms of x that determines how much water should be added to x liters of an 18% solution to reduce the concentration to 15%?

Question 902516: Write an equation in terms of x that determines how much water should be added to x liters of an 18% solution to reduce the concentration to 15%?
Found 2 solutions by richwmiller, josgarithmetic:
Answer by richwmiller(17219) (Show Source): You can put this solution on YOUR website!
x*0.18=0.15*(x+y)
x is the amount of solution
y is the amount of water to be added.

Answer by josgarithmetic(39618) (Show Source): You can put this solution on YOUR website!
Percent will be treated as weight per weight.

Let D = density of the salt solution, grams/mL, 18% solution.
Let y = MASS in grams of water to add to get 15% salt.
The reason for the factor 1000 is because I am solving with GRAMS and MILILITERS.

Algebra Steps---

, GRAMS of water.
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