Question

The sum of successive odd numbers 1, 3, 5, 7, 9, 11, 13, 15 and 17 is please answer exam going on

I will mark u as brainliest

Answer 1

Step-by-step explanation:

Given that,

A series 1,3,5,7,9,11,13,15,17.

To find,

The sum of successive odd numbers.

Solution,

The given sequence is in AP with,

First terms, a = 1

Common difference, d = 3-1 = 2

Number of terms, n = 9

The sum of nth term of an AP is given by :

S_n=\dfrac{n}{2}[2a+(n-1)d]S

n

=

2

n

[2a+(n−1)d]

So,

\begin{gathered}S_n=\dfrac{9}{2}[2\times 1+(9-1)\times 2]\\\\S_n=\dfrac{9}{2}\times (2+16)\\\\S_n=81\end{gathered}

S

n

=

2

9

[2×1+(9−1)×2]

S

n

=

2

9

×(2+16)

S

n

=81

So, the sum of successive odd numbers 1,3,5,7,9,11,13,15,17 is 81.