Hi! A new concept is being introduced and I'd like to figure out some of these examples with answers.

1.

What is the sum of the series?

2.

what is the sum of this series?

3. What is the sum of the series?

Thank you all! :)

PhoenixForever Apr 4, 2019

#1**0 **

First one

First term = 2(1) = 2

Fifth term = 2(5) = 10

Sum of series =

[ first term + last term ] * number of terms / 2 =

[ 2 + 10 ] * [ 5] / 2 =

12 * 5 / 2 =

60 / 2 =

30

CPhill Apr 4, 2019