Answer:
- 1602
Step-by-step explanation:
a = first term = 81
d = second term - first term = third term - second term
d = 64 - 81 = 47 - 64
d = - 17
Therefore,
nth - term = a + (n - 1)d
100th term = 81 + (100 - 1) (-17)
100th term = 81 + (99)(-17)
100th term = 81 - 1683
100th term = - 1602
