How do I break a long equation over lines?

Question

I am trying to add an equation in a new line. The problem is that the equation is too long for the line, and I need to break it manually. Otherwise, it just overlaps to the righ

Answer 1

I usually prefer to handle this by using the amsmath package and using the split structure. There are a bunch of useful structures in there for splitting equations across lines, but that's usually the simplest to use.

Many TeX installations will already have the package, but you can also get it from the AMS website.