Answer
$2+j,\ or, \ 2-j$
Work Step by Step
For the equation $x^2 -4x+5 = 0$, we use the quadratic formula as follows
$$ x=\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a}, \\
a=1, \quad b=-4, \quad c=5
.$$ That is,
$$ x=\frac{4 \pm \sqrt{16-20}}{2 }=2+j,\ or, \ 2-j
.$$
