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

The sum of arithmetic series is - 2119 .

Step-by-step explanation:

Given as :

The first term of series = a = - 94

The 26th term of series = = - 69

The number of term = n = 26

Now, Let The sum of arithmetic series =  

So, = × (First term + Last term)

Or,   =   × (a + )

or, = 13 × ( - 94 - 69 )

or, = 13 × ( - 163 )

or,   = - 2119

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

Hence The sum of arithmetic series is - 2119 . Answer

80

it is

(4⋅√5)2=(4)2⋅(√5)2=16⋅5=80