Question 329487
a 1500 liter tank contains 30 liters of a 70 % acid solution.
 You add x liters of a 30 % acid solution to the tank.
 Determine a function that represents the proportion of acid to the total
 solution in the final mixture
:
y = decimal proportion of acid to the total
y(x+30) = .3x + .7(30)
y(x+30) = .3x + 21
y = {{{(.3x+21)/(x+30)}}}