Question

Find the sum of the series and show your process for finding each term leading to the final sum.

Answer 1

Answer:

$\sum_{k=3}^5(-2k+5)=-9$

Step-by-step explanation:

The given series is:

$\sum_{k=3}^5(-2k+5)$

The series is not very lengthy so we can write the expanded form;

$\sum_{k=3}^5(-2k+5)=(-2(3)+5)+(-2(4)+5)+(-2(5)+5)$

This implies that;

$\sum_{k=3}^5(-2k+5)=-1+-3+-5$

$\sum_{k=3}^5(-2k+5)=-9$