10. second or 23 11. second or the one that starts at 41 and ends at 48 12. third one -1 13. third one the one with -4 at top left 14. second the one with -5 and -45 15. secondĀ or 56 16. second or -5n+19 17. third or tn=1 times (1/3)^(n-1) 18. second or -13