Question 607524
{{{x^2-2x-13=0}}}
Because we can't factorize this, use the formula:
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
a = 1, b = -2, c = -13
{{{x = (-(-2) +- sqrt( (-2)^2-4*1*(-13) ))/(2*1) }}}
{{{x = (2 +- sqrt( 4+52 ))/2 }}}
{{{x = (2 +- sqrt( 56 ))/2 }}}
{{{x = (2 +- sqrt( 4*14 ))/2 }}}
{{{x = (2 +- 2sqrt( 14 ))/2 }}}
{{{x = 1 +- sqrt( 14 ) }}}
{{{x = 1 + sqrt( 14 ) }}} or {{{x = 1 - sqrt( 14 ) }}}