Question

the sum of first n terms of AP is given as Sn- 2n^2 +3n find the sixteenth term of the AP

Answer 1

Sn=2n^2+3n
S(1)=2(1)^2+3(1)
=5=a1
S(2)=2(2)^2+3(2)
=14
S(2)-S(1)=9=a2
Now
D=a2-a1
=9-5=4