Question 4950
{{{x+3)^2-20=0}}}
{{{x^2+6x+9-20=0}}}
{{{x^2+6x-11=0}}}
Use the quadratic equation:
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
where 
A=1
b=6
c=-11
{{{x = (-6 +- sqrt( 6^2-4*1*-11 ))/(2*1) }}}
{{{x = (-6 +- sqrt( 36+44 ))/(2) }}}
{{{x = (-6 +- sqrt( 80))/(2) }}}