In this sequence there are actually two sequences. 1 sequence for the numerators and one sequence for the denominators. The following transformation applies to the sequence for the denominators : -6
This creates the following sequence: [6, 0, -6, -12, -18, -24]
The following transformation applies to the sequence for the numerators: -4
This creates the following sequence: [14, 10, 6, 2, -2, -6]
Take a good look at how to rewrite the fractions in the series to recognize the pattern.
For example, 3/7 can be rewritten as 6/14