Which two values of x are roots of the polynomial below? x^2 + 5x + 9

They are not real.
b^2 - 4ac =
b = 5
a = 1
c = 9
5^2 - 4(1)(9)
25 - 36
- 11
The quadratic formula is
x = (- b) +/- sqrt(b^2 - 4ac)
. . . . .
. . . . . . . . . . 2(a)
x = ( (- 5 +/- sqrt(-11) ) / 2
x = ( - 2.5 +/- sqrt(11) i / 2

Do you need with the x value for the minimum? its always between the two intercepts for a parabola