Solve a modulus problem with a negative sign

[Nousher]

In a video, a person discussed how to solve modulus problems with a negative sign. This is the link of that video lecture https://youtu.be/VxtB38DP8F4.

He showed two methods to solve the problem. The first method is commonly used. Later he showed another method where he used a number line and a graph.

Unfortunately, I couldn't understand his explanation properly. What is the original name of the second method he discussed in that video? If I could learn the actual name of the second method, I could googled to learn more about that.

[Guest]

A couple of points- when he say "RHS"(Right Hand Side) he actually means LHS (Left Hand Side), Also his use of "=" is strange. He says, at one point, "3= 12". I frankly wouldn't pay much attention to it. His "new method" is just the usual method worded a little diffently.