Question

(1) The 8th term of an arithmetic sequence is 12 and its 12th term is 8.
What is the algebraic expression for this sequence?​

Answer 1

Answer:

12= a+7d

8=a+11d

I hope this help you I just try to solve

Answer 2

Answer:

a8=12

a12=8

d = am-an (where m=larger no. and n = smaller)

m-n

d = 8-12

12-8

d = -4

4

d = -1

Now, using an = a + (n-1)d

a8 = a + (8-1)(-1)

12 = a - 7

a = 12 + 7

a = 19

Thus the AP will be:

19, 18, 17, 16.....