Answer:
9th term in the given sequence is -36.
Step-by-step explanation:
Here the first four terms of the sequence is 28, 20 , 12 and 4
Now, a2 -a1 = 20 - 28 = -8
a3 - a2 = 12- 20 = -8
⇒ Here, d = - 8 , a = 28
Now, n th term in an AP : [tex]a_n = a+ (n-1)d[/tex]
Here a(n) = -36
⇒ -36 = 28 + (n-1)(-8)
or, -36 = 28 - 8n +8
or, 8n = 28 + 8 + 36 = 72
or, n = 72/8 = 9
⇒ n = 9
Hence, the 9th term in the given sequence is -36.