Question

If the nth term of an ap is 2n+1 then find the sum of n terms​

Answer 1

Answer:n^2 +2n

Step-by-step explanation:

Given,

nth term = 2n+1

1st term = 2×1+1 = 2+1 = 3

Now we know,

Sum of n terms = n/2 { a + nth term of A.P.}

=> Sum = n/2 { 3+2n+1}

= n/2 {2n+4}

= n/2 × 2 (n+2)

= n (n+2)

= n^2 + 2n

Hope this helps you....