Answer:
d = - 3 and a = 1
Explanation:
The n th term of an arithmetic sequence is
= a + (n - 1)d
where a is the first term and d the common difference
Using a(10) = - 26 and a(36) = - 104, then
a + 9d = - 26 → (1)
a + 35d = - 104 → (2)
Subtract (1) from (2)
26d = - 78 ( divide both sides by 26 )
d = - 3 ← common difference
Substitute d = - 3 into (1) or (2)
(1) : a - 27 = - 26 ( add 27 to both sides )
a = 1 ← first term