Which value for a satisfies the equation 3 - 4(1 + a) = 7? a = -2 a = -6 a = 2 a = 6

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.