A chemist has 0.5 liters of an acid solution whose acid concentration is 30%. How many liters of pure water should be added to lower the
concentration to 25%?

the sum of all the angles in a triangle are equal to 180

so you can add   the 3 given angles together to equal 180:

5y + 2y + 2y = 180

or since all three angles have the same letter, combine the 3 angles to equal 180:

9y = 180

d 600 because 15*10*2=300

300+300=600

step-by-step explanation: