To determine the 8th term of a sequence, you need to know the pattern that the sequence follows. Without more information about the sequence, it is not possible to accurately determine the 8th term.
It is possible to create multiple sequences that meet the conditions given in the problem, such as:
A sequence that follows the pattern "decrease by 2, increase by 4, decrease by 6, increase by 8, decrease by 10, increase by 12,..." would have an 8th term of -14.
A sequence that follows the pattern "decrease by 6, increase by 8, decrease by 10, increase by 12, decrease by 14, increase by 16,..." would have an 8th term of 18.
Without knowing the pattern that the sequence follows, it is not possible to determine the 8th term with certainty.