Question 816063
Well we start off by using the quadratic equation in conjunction to the formula given. 

{{{x = (-2 +- sqrt( 2^2-4*1*5 ))/(2*1) }}}

This gives us: 

{{{(-2 +- sqrt (4-20))/(2) }}} 

This then leads us to: 

{{{ (-2 +- sqrt (-16))/(2) }}} 

and you should know since {{{ sqrt(-16) }}} is technically impossible to do but we can switch this to an imaginary number. So our equation would be: 

{{{ (-2/2) +- sqrt (16i)/(2) }}}

Then we further equation along by: 

{{{ (-2/2) +- (4i)/ (2)) }}} 

Then finally we reduce: 

{{{x =  -1 +- 4i/2}}}