Question

If sum to 'n' terms of an AP is 3n^2+4n then the CD of AP is​

Answer 1

Step-by-step explanation:

sum of terms S=3n^2+4n

n/2(2a+(n-1)d)=3n^2+4n

2a+(n-1)d=6n+8

2a+(n-1)d=6(n-1+1)+8

2a+(n-1)d=6(n-1)+6+8

2a+(n-1)d=14+6(n-1)

2a=14,a=7

d=6