Question 557710
{{{ x^2 - x = -10 }}}
{{{ x^2 - x + 10 = 0 }}}
This is in the form
{{{ ax^2 + bx + c = 0 }}}
so I can use the quadratic formula:
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} 
{{{ a = 1 }}}
{{{ b = -1 }}}
{{{ c = 10 }}}
{{{x = (-(-1) +- sqrt( (-1)^2-4*1*10 ))/(2*1) }}} 
{{{x = ( 1 +- sqrt( 1 - 40 )) / 2 }}} 
{{{x = ( 1 +- sqrt( -39 )) / 2 }}} 
{{{x = ( 1 +- sqrt( -1 )*sqrt(39) ) / 2 }}} 
{{{ x = ( 1 + sqrt(39)*i ) / 2 }}}
and
{{{ x = ( 1 - sqrt(39)*i ) / 2 }}}
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Check answer:
{{{ x^2 = (( 1 - sqrt(39)*i ) / 2)^2 }}}
{{{ x^2 = ( 1 - 2*sqrt(39)*i - 39 ) / 4 }}}
{{{ x^2 - x =  ( 1 - 2*sqrt(39)*i - 39 ) / 4 - ( 2 - 2*sqrt(39)*i ) / 4  }}}
{{{ x^2 - x = (1/4)*( -38 - 2 ) }}}
{{{ x^2 - x = -10 }}}
OK