Question 122493
{{{(x-10)(x-2)=-20}}}
Use the FOIL method (First, Outer, Inner, Last)
{{{(x)(x)+(x)(-2)+(-10)(x)+(-10)(-2)=-20}}}
{{{x^2-2x-10x+20=-20}}}
{{{x^2-12x+20=-20}}}
{{{x^2-12x+40=0}}}
{{{x = (-(-12) +- sqrt( 12^2-4*(1)*(40) ))/(2) }}} 
{{{x = (12 +- sqrt( 144-160 ))/(2) }}} 
{{{x = (12 +- sqrt( -16 ))/(2) }}} 
{{{x = (12 +- 4*sqrt( -1 ))/(2) }}} 
{{{x = 6 +- 2*sqrt( -1 ) }}} 
{{{x = 6 +- 2i }}}