How do you write an equation for an arithmetic sequence?

To write an equation for an arithmetic sequence, you need to identify the first term and the common difference between consecutive terms.

The general form of an arithmetic sequence is:

a_n = a₁ + (n – 1)d

In this equation:

• a_n is the nth term of the sequence.
• a₁ is the first term of the sequence.
• d is the common difference.
• n is the term number.

For example, if your first term (a₁) is 3 and your common difference (d) is 5, the equation would look like:

a_n = 3 + (n – 1)5

This can also be simplified to:

a_n = 5n – 2

With this equation, you can find any term in the sequence by substituting the term number (n) into the equation.