Determine the missing value based on the length of two secant lines

The video tutorial covers the concept of secant lines in geometry, explaining the relationship between their lengths. It demonstrates how to apply the secant line formula and solve the resulting equation using the distributive property and factoring. The tutorial also discusses the zero product property to find the solution, emphasizing the importance of understanding algebraic techniques.

How do you determine the two numbers that multiply to give -36 and add to give 9?

What are the possible values of X after solving the equation, and why is one of them not valid?