Question 874521
You can always check your answer in the original equation.
{{{-2^2-6(-2)-12=0}}}
{{{-4+12-12=0}}}
{{{-4=0}}}
False, so no it's not a solution.
{{{-x^2-6x-12=0}}}
{{{x^2+6x+12=0}}}
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
 {{{x = (-6 +- sqrt( 6^2-4*1*12 ))/(2*1) }}}
{{{x = (-6 +- sqrt( 36-48 ))/(2) }}}
{{{x = (-6 +- sqrt( -12 ))/(2) }}}
{{{x = (-6 +- sqrt( 12 )sqrt(-1))/(2) }}}
{{{x = (-6 +- 2sqrt( 3 )i)/(2) }}}
{{{x = -3 +- sqrt( 3 )i }}}