Question

the sum of the first n terms of an a.p is given by sn=4nsquare-3n. find the 16th term of the a.p

Answer 1

4n^2-3n
put n=1
4-3=1
s1=a1=1
S2=put n= 2
s2=10
s2=a1+a2
10=1+a2
a2=9
d=a2-a1
d=8
a16=a+(n-1)d
=1+(16-1)8
=120