SOLUTION
We want to complete the sequence below.
-30, -22, -14, -6, 2
From the sequence above, we can see that
[tex]\begin{gathered} -30+8=-22 \\ -22+8=-14 \\ -14+8=-6 \\ -6+8=2\text{ and finally } \\ 2+8=10\text{ } \end{gathered}[/tex]So the common difference is 8.
Hence the answer is 10