I'm trying to help a math teacher convert some quizzes to Canvas. The problem we're running into is how to get rich text to display as answers in quizzes.

For instance, if one of the possible answers is x^3 + 2^x - 7 we're not seeing a way to display that with superscripts for the powers instead of ^. We can create the phrase in the rich text editor for the question, but when we copy and paste it to the answer all the formatting is lost.

Any hints about how to deal with this?

You can create the equation using the Math Editor. You can find instructions for that here: How do I use the Math Editor in the Rich Content Editor?

To use the Math Editor in the answers, you have to click the little pencil icon to get the full rich content editor.

It looks like Canvas converts the equation into an image file. That means you can switch over to the HTML view and copy/paste the code into the html view of another content area. That's only useful if you're using the exact same equation over and over again with no modification.

When you construct via the math editor, you can click to "switch view to Advanced" which will show you the LaTeX code which you can copy and paste from math editor to math editor. You'll have to be in the advanced view in both editors for that.