36,6,-24,-54 arithmetic sequences

Since the values are lowering each time and it is an arithmetic sequence, we can assume that each number is being subtracted by the same number. We can figure this out by setting up an equation taking two values from the sequence.

Let's use 36 and 6

36 - x = 6 which gives us 30. We can check our work by subtracting each value by 30 starting from 36.