Find the missing terms of each arithmetic sequence.

1. x, _____, 9x
2. -4, _____, _____, 5
3. -5, _____, _____, _____, _____, 3
4. _____, 6, _____, _____, _____, 30
5. _____, _____, _____, 2, -2, -6, _____,​