Question 1119497
The nth term of an arithmetic sequence is a(n) = a + (n-1)d 
where d = common difference, a = 1st term
a(18) - a(8) = a + 17d - (a + 7d) = -96 - 4 = -100
Thus 10d = -100 -> d = -10
a(8) - a = a + 7d - a = 7d = -70
a = 4 - -70 = 74
Thus a(n) = 74 - 10(n-1)