Question 235514
{{{9h^2 - 6h + 7 = 0}}}
{{{h = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
a,b and c in this formula are the coefficients 
in the general formula:
{{{ax^2 + bx + c = 0}}} (substitute h's for x's)
{{{a = 9}}}
{{{b = -6}}}
{{{c = 7}}}
{{{h = (-(-6) +- sqrt( (-6)^2-4*9*7 ))/(2*9) }}}
{{{h = ( 6 +- sqrt( 36 - 252 ))/18 }}} 
{{{h = ( 6 +- sqrt( -216 ))/18 }}}
{{{h = ( 6 +- sqrt( -6*36 ))/18 }}} 
{{{h = ( 6 +- 6*sqrt( -6 ))/18 }}}
{{{h = 1/3 + sqrt(6)i/3}}}
and
{{{h = 1/3 - sqrt(6)i/3}}}
({{{i = sqrt(-1)}}})