Question 312441
{{{ X(X+1)=27}}} 
{{{ X^2+X=27}}} 
{{{ X^2+X-27=0}}} 
Use the quadratic formula,
{{{ X = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} 
{{{X = (-1 +- sqrt( 1^2-4*1*(-27) ))/(2*1) }}} 
{{{X = (-1 +- sqrt( 1+108 ))/2 }}} 
{{{highlight_green(X = (-1 +- sqrt(109 ))/2) }}}