Question

2. Find the sum of the arithmetic series if
a = -94, a26 = -69, and n = 26

Answer 1

The sum of arithmetic series is - 2119 .

Explanation:

Given as :

The first term of series = a = - 94

The 26th term of series =
`a_2_6` = - 69

The number of term = n = 26

Now, Let The sum of arithmetic series =
`s__n`

So,
`s__n` =
`(n)/(2)` × (First term + Last term)

Or,
`s_2_6` =
`(26)/(2)` × (a +
`a_2_6` )

or,
`s_2_6` = 13 × ( - 94 - 69 )

or,
`s_2_6` = 13 × ( - 163 )

or,
`s_2_6` = - 2119

or, the sum of 26 arithmetic series =
`s_2_6` = - 2119

Hence The sum of arithmetic series is - 2119 . Answer