Question

What is one root of this equation?
2x^2 - 4x + 9 = 0

Answer 1

Just find what x is and choose between the two x-values you found to be a root.

Answer 2

You can find the roots with the quadratic formula:

given a polynomial \(ax^2+bx+c=0, a\ne 0\)
\[x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}\]