There are twice as many liters of water in one container as in another. if 8 liters of water are removed from each of the two containers, there will be three times as many liters of water in one container as in the other. how many liters of water did the smaller container have to begin with?

Suppose the # of litres in the small container is 'x'.
This would make '2x' litres of water in the larger container.
After taking 8 litres from both containers, the following equation can be written:

(2x-8) = 3 (x-8)

Open the brackets:

2x-8 = 3x-24

Collect like terms:

x = 16

There were 16 litres in the smaller container