Question

the sum of first n term of an ap is given by SN is equal to 2n square + 3n find the 16 term of an ap​

Answer 1

Answer:

put n=1 then

1st term is 5

put n=2 then sum of two terms is 14

2nd term is 9

a=5

d=4

16th term is a+15d

=5+60

=65

ok

follow

me

gys

Answer 2

Sn = 2n^2 + 3n

If n=1,

S1= 2x1^2 +3x1

= 5

We know, *S1=a1*

---> a= 5

If n=2,

S2= 2x2^2 + 3x2

=14

Sn= n/2[2a+(n-1)d]

14= 2/2[2x5+(2-1)d]

14= 10+d

d= 14-10

= -4

a16= a+15d

=5+ 15x-4

= -55

------

Please mark it as brainliest.

Thank you