Charlie mixes 15 liters of 17% acid solution with a 29% acid solution, which results in 23% acid solution. let x represent the number of liters of 29% solution used and let y represent the number of liters of mixture. which system of equations can be used to find the number of liters of 29% acid solution in the mixture? y = x + 15; 0.29y = 0.23x + 2.55 y = x + 15; 0.23y = 0.29x + 2.55 y = x + 15; 0.23y = 0.29x + 4.35 y = x + 15; 0.29y = 0.23x + 3.45