Python question (nice update!)

So I reset my progress on python because of the new recent update. First off, let me just say that you guys did a great job on updating the course. I find it more informative and even a bit more engaging than the first time. However, I do have a question. I’m currently on the first lesson, on section 7/14. So what do the += and -= mean?

If you already did the python course, you should know? There shorthands, both these lines are the same:

x = x + 5
x += 5

the second line just uses a shorthand (assuming x is defined and is a integer)

Well, I actually didn’t know, and didn’t ask the first time. The first few times I went through the course before the update I kind of ignored it, and thought it wasn’t that important. I decided to finally ask for help. Thanks?