Question

3. Find the 11 term from the last term (towards the first term) of the AP
12, 8, 4, ..., -84.​

Answer 1

Answer:

12,8,4,......,-84.

a=12. d=a2-a1=8-12=-4. an=-84. n=11. a11=?.

an=a+(n-1)d

-84=12+(n-1)(-4).

-84-12=(n-1)(-4).

-96=(n-1)(-4).

-96/-4=(n-1).

96/4=(n-1).

24=(n-1).

n=24+1.

n=25.

(or).

an=a+(n-1)d.

a11=12+(11-1)(-4).

a11=12+(10)(-4).

a11=12-40

a11=-28.

I think this is your answer.