In class, my math instructor showed us how to find 5th degree polynomials on the classwiz, but I don't remember how to do it and keep messing up. I think he either input something like Ax^{5}+Bx^{4}+......C then input the values for A, B, etc and found x like that. Or he somehow used the spreadsheet. I've tried multiple ways but can't figure it out.

I know the classwiz has an icon for polynomials of degrees of 2-4, and know how to use that, but I can't figure out how to find a 5th degree