Question Video: Evaluating the Sum of a Finite Series | Nagwa Question Video: Evaluating the Sum of a Finite Series | Nagwa

# Question Video: Evaluating the Sum of a Finite Series Mathematics • Second Year of Secondary School

## Join Nagwa Classes

Attend live General Mathematics sessions on Nagwa Classes to learn more about this topic from an expert teacher!

Evaluate ∑_(𝑟 = 2) ^(6) −25.

00:59

### Video Transcript

Evaluate the sum of negative 25 where 𝑟 takes values from two to six.

As the value we are trying to sum here is a constant, we might think that the answer is just negative 25. However, the sigma or sum notation tells us that our series will have five terms, when 𝑟 equals two, three, four, five, and six. Each of these terms will be equal to the constant negative 25. This means that we need to add negative 25, negative 25, negative 25, negative 25, and negative 25. This is the same as multiplying negative 25 by five, giving us negative 125.

## Join Nagwa Classes

Attend live sessions on Nagwa Classes to boost your learning with guidance and advice from an expert teacher!

• Interactive Sessions
• Chat & Messaging
• Realistic Exam Questions