Hey there, thanks for asking such a good question! Let's take a look...
We can start with what "x" is. Here is how it is defined.
6ccd3814-25ba-4050-9cbc-7fe354c1b15f-image.png
Now let's try and figure out what "x+1" is, by adding 1 to both sides.
0836ee48-e700-45f6-8f3b-be8be34b36f1-image.png
Wait a second, this looks a little familiar... where have we seen this before?
Yes! It's just the denominator of the fraction! (remember the dots just mean the pattern keeps going)
61be5a5c-713c-46ff-94ad-953ab67c5f5c-image.png
So since what is in the blue box and "x+1" are the same thing, we can replace one with the other.
18c448b4-3ae2-4e6c-93dd-90efe5bb4a50-image.png
There you go! The denominator is just "x+1".
I hope that answers your question. If you have any other questions or clarifications, just shoot us another email.
Best,
"The Daily Challenge Team