Solve the Sequence Formula n²-n: Finding the Fifth Element

Below is the rule for a sequence written in terms of $n$:

$n^2-n$

What is the 5th element?

To solve this problem, we will follow these steps:

• Step 1: Understand the formula given for the sequence.
• Step 2: Substitute $n = 5$ into the formula to find the 5th element.
• Step 3: Simplify the expression to find the solution.

Now, let's work through each step:

Step 1: We have the formula for the sequence as $a_n = n^2 - n$.

Step 2: We will substitute $n = 5$ into the formula:

$a_5 = 5^2 - 5$

Step 3: Calculate the expression:

$a_5 = 25 - 5$

$a_5 = 20$

Therefore, the 5th element of the sequence is $20$.