Write an equation for the n th term of the arithmetic seqeuence. Then find a10. 10,0,-10,-20

Question

kinda stuck on this problem, need help.

Answer 1

After reading Tom K's answer, check out this table:

Answer 2

For arithmetic progressions, an = a1 + (n-1)d

a1 = 10

d = -10

Thus, an = 10 + (n-1)(-10) = 10 + -10n + --10 = 20 - 10n

a10 = 20 - 10(10) = 20 - 100 = -80