Here's the question you clicked on:
MacPfister
If 2 + sqrt(3) is a polynomial root, name another root of the polynomial and explain how you know it must also be a root. (Explain in 1 or 2 sentences)
I guess they are defining this polynomial to have real coefficients even though they didn't say that. So when you solve \[ax^2+bx+c=0\] You get \[x=\frac{-b \pm \sqrt{b^2-4ac}}{2a}\]. See of you can use that here. :)
I'm also assuming that this polynomial has a quadratic factor. Such a weird question. Seems incomplete.
I need it in sentences.. :/ sorry
That doesn't answer the question either though, cause it's asking what would be another root if one of the polynomial roots is 2+ sqrt(3)
That is 2 general solutions to a general quadratic above.
A quadratic is a polynomial.