Question

5. Which term of an A.P.16, 11, 6, 1,... is -54 ?
6. Find the middle term(s) of an A.P. 9, 15, 21, 27...183.​

Answer 1

Answer:

a=16 d= -5 an= -54

a+(n-1)d=an

16+(n-1)-5= -54

-5n+5= -54-16

-5n= -70-5

-5n= -75

n=15