Question

Sum of n terms of Ap:1+5+11+.....is........
Options:
A)3n^2+4n
B)4n-3n^2
C)3n^2-4n
D)4n^2-3
We need with solution
Answer should be in nth term

Answer 1

Answer:

2n^2 - n

Step-by-step explanation:

a =1

d= 5-1=4

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

n/2[2*1+(n-1)4]

n/2[2+4n-4]

n/2[4n-2]

2n^2-n