Mixing Solutions to Find Concentration

In a chemistry lab, a solution is prepared by mixing two types of solutions, Solution A and Solution B. Solution A contains 30% concentration of a certain acid, and Solution B contains 70% concentration of the same acid.

If 2 liters of Solution A is mixed with $$x$$ liters of Solution B, the resulting mixture has a concentration of 54% acid. Your task is to determine the value of $$x$$.