The quadratic formula tells you that the solutions to
[tex]ax^2+bx+c=0[/tex]
are given by
[tex]x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]
Filling in a=1, b=-4, c=5, this becomes
[tex]x=\dfrac{-(-4)\pm\sqrt{(-4)^2-4(1)(5)}}{2\cdot 1}\\\\x=\dfrac{4\pm\sqrt{-4}}{2}\\\\x=2\pm i[/tex]
The zeros are 2+i andd 2-i.
