Respuesta :

Answer:

21 gallons.

Step-by-step explanation:

Let the number of gallons that the tank holds be x gallons.

1/2x + 7 = 5/6 x

5/6x - 1/2x = 7

5/6 x - 3/6 x = 7

1/3 x = 7

x = 21.

(edit: nvm about whatever i wrote down)