Question 6841
I get the following, using the quadratic equation:

{{{x = (4 +- sqrt(16-40))/4}}}
{{{x = (4 +- sqrt(-24))/4}}}
{{{x = (4 +- sqrt(-4(6)))/4}}}
{{{x = (4 +- 2i(sqrt(6)))/4}}}
{{{x = 1 +- (1/2)i(sqrt(6))}}}

Checking: for {{{x=1+(1/2)i(sqrt(6))}}}
{{{x^2=1+i(sqrt(6))-(6/4)}}}
{{{2x^2=2+2i(sqrt(6))-3}}}
{{{-4x=-4-2i(sqrt(6))}}}
{{{x^2-4x+5=2+2i(sqrt(6))-3-4-2i(sqrt(6))+5=0}}}