Question

Consider the arithmetic sequence 11, 19, 27, 35, ....
a.) Find the 11th term of the sequence.
b.) Find the sum of the first 15 terms of the sequence.
c.) The sum of the first n terms is 2090. Find the value of n.​

Answer 1

Answer:

(a) Tn= a + (n-1)d

d= 19-11

= 8

a= 11

n=11

therefore

11th term of the sequence= 11 +(11-1)8

=11+ 10×8

= 91

(b) use same method which is used above

(c) sum of the first n terms = S = n/2[2a + (n − 1) × d]

all the values are given above...

solve this by yourself... u can do it i knw...:)