Algebra help please!

Question

a chemist wishes to mix a solution that is 10% acid. She has on hand 12 liters of a 6% acid solution and wishes to add some 14% acid solution to obtain the desired 10% acid solution. How much 14% acid solution should she add?

Liters of solution 12 x ? (do not simplify)
Percent acid (as a decimal)
0.06
0.14
0.10
Liters of Pure Acid
?
?
?

Answer 1

You have to work with the amounts of acid:

6% of 12 liters plus 14% of x liters equals 10% of x+12 liters:

 

0.06(12) + 0.14x = 0.1(x+12)

 

0.72 + .14x = 0.1x + 1.2

 

0.04x = 0.48

 

x = 12 liters of 14% acid solution