algebra
posted by geena .
a scientist has a 25% acid solution.how many liters of each does the scientist need to make 15L of a solution that is 28%.write a system of equations and solve using any method.

you need to specify some other concentration. You say "liters of each" but only name the 25% solution.
for example, if he has 31% solution, then adding 7.5L of 25% to 7.5L of 31% will give 15L of 28%.