2.	A chemist wants to make 4 liters of a 7% acid solution by mixing a 10% acid solution and a 4% acid solution. How many liters of each solution should the chemist use? Write your answer as a complete sentence.  Be sure to: •	Define your variable and expressions for the quantities. •	Write an equation that models the problem. •	Solve the equation. •	State the answer in a complete sentence.