Given the first four terms of an arithmetic sequence find the rule

The video tutorial explains how to find the formula for an arithmetic sequence. It begins by converting terms to fractions to simplify subtraction and identify the common difference. The common difference is found to be -5/2. The tutorial then applies the arithmetic sequence formula, a_n = a_1 + (n-1) * d, and finalizes it by combining terms to get the formula a_n = -5/2n + 13/2.

Explain how to apply the distributive property to the formula for a sub N.

What is the final formula for a sub N after combining the terms?