Question 204502
because it can't be factorized, we can use this formula:

{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}

{{{x = (-8 +- sqrt(8^2-4*1*(-1)))/(2*1) }}}
{{{x = (-8 +- sqrt(16+4))/(2)}}}
{{{x = (-8 +- sqrt(20))/(2)}}}
{{{x = (-8 +- sqrt(4*5))/(2)}}}
{{{x = (-8 +- 2*sqrt(5))/(2) }}}
{{{x = (-4 +- sqrt(5))}}}

so,
x1 = {{{-4 + sqrt(5)}}}
x2 = {{{-4 - sqrt(5)}}}