Question

The sum of first n term of an AP is given by s©n= 2n^2 + 3 n. Find the sixteenth term of the Ap

Answer 1

Answer: 65

Step-by-step explanation:

please see the steps in the pics below

i hope  it is clear................

Answer 2

Answer:

Step-by-step explanation:

Putting n=1

Sn=2(1)^2 + 3(1)

Sn=2+3

Sn=5 ..........(sum of 1st term)

Putting n=2

Sn=2(2)^2 + 3(2)

Sn=8 + 6

Sn=14 .........(sum of 2 terms)

Putting n=3

Sn=2(3)^2 + 3(3)

Sn=18 + 9

Sn=27 ...........(sum of 3 terms)

Since sum of 2 terms is 14

5+a2=14

a2=9

a1=5

a2=a+(n-1)d

a2=5+(2-1)d

a2=5+d

9-5=d

4=d

a16=a+(16-1)d

a16=5+(15)4

a16=65