How to find the LCD so that you can add two rational expressions

The video tutorial covers the concept of LCD (Least Common Denominator) and its variations, emphasizing that it is not just a single number but can have multiple representations. It further explains the process of working with equivalent fractions, including multiplying by the denominator to achieve equivalent values. The tutorial concludes with forming equations using these fractions, demonstrating how to combine and simplify them effectively.

Why does the teacher mention multiplying by the denominator again?

What is the final equation produced by the teacher?