Question

Find the series shown.

Answer 1

Answer:

C $11+13+15+17+...$

Step-by-step explanation:

Consider the series

$\sum\limits_{n=3}^{\infty}(2n+5)$

The nth term of series is $a_n=2n+5$

The bottom index tells you that n starts changing from 3, so

$a_3=2\cdor 3+5=11\\ \\a_4=2\cdot 4+5=13\\ \\a_5=2\cdot 5+5=15\\ \\a_6=2\cdot 6+5=17\\ \\...$

Thus, the sum of all terms is

$11+13+15+17+...$