Factor the denominator to help you simplify a rational expression

The video tutorial explains how to simplify rational expressions by factoring. It begins with an introduction to the problem and the importance of factoring. The instructor emphasizes that simplification cannot occur across addition and subtraction. The AC method is used to identify perfect square trinomials, and the final steps of simplification are demonstrated, highlighting the importance of understanding the result.

What is the significance of having a '1' left in the numerator after simplification?

After factoring, what is the result of X - 4 divided by X - 4?