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 : -8
This creates the following sequence: [-10, -18, -26, -34, -42, -50]
The following transformation applies to the sequence for the numerators: -9
This creates the following sequence: [15, 6, -3, -12, -21, -30]
Take a good look at how to rewrite the fractions in the series to recognize the pattern.
For example, -2/3 can be rewritten as -10/15