Question

Solve: $x^2+4x+5=0$

Answer 1

$x^2+4x+5$ when compared to standard quadratic equation $a{x}^2+bx+c=0$ gives

$a=1$,$b=4$ and $c=5$

$\because x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}\therefore x=\frac{-4\pm \sqrt{4^2-4\times 1\times 5}}{2\times 1}=\frac{-4\pm \sqrt{-4}}{2}=\frac{-4}{2}\pm \frac{2\sqrt{-1}}{2}=-2\pm i$