Just for clarification purposes in case someone other than me sees the word LaTeX and gets all excited ...
The code that is showing is HTML, not LaTeX.
Latex would have been \(x^3+6x^2-2x-12\).
Regardless, it's good to know that Canvas is aware of it and a solution is coming.
Edit: So I discovered something new this morning. The community software now supports LaTeX entry. Awesome! But that means that my LaTeX example didn't come through as LaTeX. I don't know how many of my other posts that ruined where I was trying to tell people how to enter LaTeX, but it's still awesome.
Here's what it should be, but without the space between the \ and the parentheses.
Latex would have been \ (x^3+6x^2-2x-12\ ).