Need help please ASAP

Megan and desmond each add the same amount of water to their aquarium megan makes 5 ml of chemical solution with every gallon of water for her aquarium desmond mixed 8 ml of chemical solution for every 2 gallon of the water for his aquarium.

Which of the following sets represents mun? (2,5,8) (4,7) (3,4,6,7,9) {3,6,9

Which statement is true about the graphs of the two line y=-8x-5/4 and y=1/8x+4/5